Miscellaneous MSK
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 57

14:00         3990.     Ultra-Short TE-Enhanced T2* Mapping of Cartilage

Ashley Williams1, Yongxian Qian2, David Bear1, Fernando Boada2, Constance Chu1

1Cartilage Restoration Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA; 2MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA

Ultra-short TE-enhanced T2* mapping permits detection of short T2 components in articular cartilage that are not well-captured by standard T2 mapping. This study compared T2 and T2* maps to spatially registered microscopic optical coherence tomography and polarized light micrscopy examinations (PLM) of explanted human tibial plateau cartilage. Zonal stratifications observed on T2* maps and OCT were similar to those observed within the collagen matrix arrangement seen by PLM. Focal T2* lesions within the transitional zone corresponded to areas of collagen matrix derangement. High-resolution UTE-enhanced T2* mapping discriminates normal from abnormal collagen architecture in vitro.

14:30         3991.     Ultrashort Echo Time (UTE) Spin Echo (SE) MR Imaging for the Evaluation of Tmj: Benefits Over Gradient Echo Acquisition

Hatice Tuba Sanal1, Jiang Du1, Atsushi Takahashi2, Sheronda Statum1, Richard Znamirowski1, Graeme M. Bydder1, Christine B. Chung1

1Radiology, UCSD, San Diego, CA, USA; 2Applied Science Laboratory, GE Healthcare, Milwaukee, WI, USA

UTE SE MRI FOR EVALUATION OF TMJ: BENEFITS OVER GE ACQUISITION

15:00         3992.     Ultrashort TE Imaging with Rescaled Digital Subtraction (UTE RDS)

Jiang Du1, Christine B. Chung1, Graeme M. Bydder1

1Radiology, University of California-San Diego, San Diego, CA, USA

Imaging of short T2 tissues often requires not only a short TE but efficient suppression of the signal from surrounding long T2 species which may have much higher MR signals. Dual echo acquisition and subtraction has been used to improve short T2 contrast. This approach is simple and effective in many cases. However, the short T2 contrast may be significantly reduced with high resolution imaging due to increased echo spacing and susceptibility effect. Here we present a technique called UTE with Rescaled Digital Subtraction (UTE-RDS) which provide high positive contrast for multi-slice 2D imaging of short T2 species.

15:30         3993.     3T MR Imaging of the TMJ Using UTE Sequence in Volunteers

Hatice Tuba Sanal1, Jiang Du1, Atsushi Takahashi2, Sheronda Statum1, Richard Znamirowski1, Graeme M. Bydder1, Christine B. Chung1

1Radiology, UCSD, San Diego, CA, USA; 2Applied Science Laboratory, GE Healthcare, Milwaukee, WI, USA

3T MRI of TMJ Using UTE sequence in Volunteers

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 57

13:30         3994.     Intra-Articular Hyaluronic Acid Treatment of Knee Osteoarthritis in Rats Investigated by Quantitative T2 Measurements

Ping-Huei Tsai1, Ming-Chung Chou2, Ming-Huang Lin3, Chien-Yuan Lin3, Hsiao-Wen Chung1, Heng-Sheng Lee4, Guo-Shu Huang2

1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Radiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan; 3Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan; 4Department of Pathology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan

The purpose of this study is to investigate the relationship between the HA treatment and articular cartilage T2 in a rat model of OA by MR quantitative measurements. Our preliminary findings suggest that HA treatment may prevent the degradation of knee cartilage and has a potential to promote the regeneration on the OA knee, which is observable by longitudinal quantitative MR T2 measurements as shown in the slowdown of the tendency of increasing T2 value.

14:00         3995.     Double Inversion Recovery (DIR) MR Imaging to Improve a Contrast in Effusion Regions of the Knee

Geon-Ho Jahng1, Wook Jin1, Hyun Cheol Kim1, Dal Mo Yang1

1Radiology, East West Neo Medical Center, Kyung Hee University, Seoul, Korea

To investigate an improved contrast of effusion areas in knees, computer simulations were performed to obtain optimum values of two inversion delay times, TI1 and TI2, to suppress both water fluid and fat signals. After then, we applied the DIR sequence to effusion imaging in human knees. The timing to enhance effusion contrast was found to be TI1=2800msec and TI2=220msec. In this study, we compared the imaging contrast of DIR sequence with and without contrast-enhanced proton-density-weighted and T1-weighted imaging sequences. The DIR sequence may be useful to quantify synovium amounts without using a contrast agent in knee.

14:30         3996.     Contrast Enhanced Ultrashort Echo Time MRI of the Achilles Enthesis in Normal Volunteers and Psoriatic Arthritis.

Richard Hodgson1, Andrew Grainger2, Laura Coates, Philip O'Connor2, Robert Evans2, Matthew Robson3

1University of Leeds, Leeds, UK; 2Chapel Allerton Hospital; 3University of Oxford

The aim of this study was to compare contrast-enhanced ultrashort echotime MRI and power Doppler ultrasound of the Achilles enthesis in normal volunteers and psoriatic arthritis. Images were obtained from 10 subjects. Ultrasound and UTE gave complementary anatomical information; UTE showed fascicular structure and fibrocartilage whereas ultrasound showed subfascicular structure and bursal extent. Strongly T1 weighted and magnetization transfer images gave good UTE contrast. UTE imaging showed focal tendon enhancement in early psoriatic arthritis which was not visible with conventional MRI. This suggests it may be useful for assessing increased vascularity in addition to structural change in early psoriatic arthritis.

15:00         3997.     Longitudinal Changes in Rheumatoid Arthritis After Rituximab Assessed by Quantitative and Dynamic Contrast Enhanced High-Resolution 3-Tesla-MR Imaging

Jan Fritz1,2, Michael Fenchel2, Claus D. Claussen2, John A. Carrino, Marius S. Horger2

1The Johns Hopkins University School of Medicine, Baltimore, MD, USA; 2Eberhard-Karls-University Tübingen

Longitudinal quantitative and dynamic contrast enhanced high-resolution 3 Tesla magnetic resonance imaging of the metacarpophalangeal joint shows that intravenous Rituximab administration for the treatment of rheumatoid arthritis is associated with a significant decrease of the inflammatory activity of synovitis with a minimum at 26 weeks and increasing activity thereafter suggesting recurrence. Intra-osseous inflammation is not influenced significantly. Erosions progressed significantly over time. There appears to be an inverse relationship of the significantly decreasing disease activity score and significantly increasing volume of the erosions, suggesting subclinical disease progression.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 57

13:30         3998.     Sodium In Vivo Measurement of T1 and T2* Relaxation Times of Articular Cartilage at 7 Tesla

Stefan Zbyn1, Vladimir Juras1,2, Wolfgang Bogner1, Pavol Szomolanyi1,2, Goetz H. Welsch1, Michal Bittsansky1, Vladimir Mlynarik3, Ewald Moser1, Siegfried Trattnig1

1MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 2Institute of Measurement Science, Department of Imaging Methods, Bratislava, Slovakia; 3Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland

In this study we employed the standard spoiled gradient echo sequence (GRE) to investigate sodium T1 and slow component of T2* (T2S*) relaxation times at 7 Tesla in vivo. We demonstrated the feasibility of sodium relaxation times measurements using GRE sequence and reported sodium T1 and T2S* times in good agreement with previously published values. Since the standard deviation of relaxation times of cartilage and homogenous phantoms are comparable, we believe that the range of observed relaxation times of cartilage is also small. Therefore we can expect that this method will be useful in detecting early stages of osteoarthritis.

14:00         3999.     Rapid 3D-Sodium MRI of Knee Joint In-Vivo at 7T

Ligong Wang1, Yan Wu1, Gregory Chang1, Niels Oesingmann2, Mark E. Schweitzer1, Alexej Jerschow3, Ravinder R. Regatte1

1Radiology, NYU Langone Medical Center, New York, NY, USA; 2Siemens Medical Solutions, USA; 3Chemistry Department, New York University, NY, US

The main purpose of this work was to demonstrate the feasibility of acquiring high resolution, isotropic 3D-sodium knee images of healthy and OA patients in vivo at 7T with clinically acceptable scan times via 3D-radial acquisition. The preliminary results suggest that the sodium imaging at 7T may be a viable potential alternative for OA imaging.

14:30         4000.     Ultrashort Echo Time Imaging of Cortical Bone at 7 Tesla Field Strength

Roland Krug1, Peder E. Larson1, Chunsheng Wang1, Andrew J. Burghardt1, Douglas A.C. Kelley2, Thomas M. Link1, Xiaoliang Zhang1, Dan Vigneron1, Sharmila Majumdar1

1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA; 2GE Healthcare Technologies, San Francisco, CA

More solid or semi-solid tissues such as trabecular and cortical bone have little to no signal in conventional MRI scans because of their ultra short T2. In this feasibility study we have implemented a 3D ultra-short TE sequence on a 7T and 3T MR scanner and compared its performance using three fresh cadaveric radii specimen. We found a significant increase in SNR at 7T but no significant different T2 values between the field strengths. We concluded that UHF MRI at 7T has great potential for imaging tissues with short T2. This is mainly due to the significant increase in SNR.

15:00         4001.     Multiparametric Analysis of Healthy and Diseased Articular Cartilage at 17.6 T and Correlation with Histology

Jose G. Raya1, Gerd Melkus2, Olaf Dietrich, Silvia Adam-Neumair3, Elisabeth Mützel4, Maimilian F. Reiser5, Peter Jakob2, Christian Glaser4

1Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, Universisty of Munich, Munich, Germany; 2University of Würzburg, Germany; 3Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, University of Munich; 4University of Munich, Germany; 5Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, University of Munich, Germany

A large collective of samples of patellar cartilage (n=38 healthy, n=11 moderate osteoarthritis (OA) and n=7 severe OA) have been multiparametric analyzed at 17.6T. For each sample maps of T2, T1, ADC, FA and water fraction volume (WFV) were obtained. After imaging, samples underwent histology and proteoglycans were stained with safranin’O. A progressive loss of the tangential zone with OA grade is observed in MR, This coincides with the continuous proteoglycan loss from the articular surface observed in histological sections. Increased ADC, T1 and WVF were found in regions with low proteoglycans. FA does not depended on proteoglycan content.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 57

13:30         4002.     MRS Characteristics of Creatine Deficiency Syndrome

Ruppen Nalbandian1,2, Hyla Allouche-Arnon1,2, J. M. Gomori1, Simon Edvardson3, Orly Elpeleg4, Rachel Katz-Brull1

1Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 2Department of Physiology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel; 3Pediatric Neurology Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 4Metabolic Diseases Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel

Creatine (Cr) and phosphocreatine (PCr) are essential for the storage and transmission of phosphate-bound energy in muscle and brain. Therefore, Cr deficiency is a severe condition leading to developmental delays. Two siblings were suspected to suffer from Cr deficiency syndrome following the clinical phenotype and homozygosity mapping. Brain MRS confirmed the Cr deficiency diagnosis and was in agreement with the rare mutation in a gene encoding the AGAT enzyme (the first enzyme in the Cr biosynthetic pathway). We report on the muscle and brain 1H-MRS characteristics of patients with the rare AGAT deficiency.

14:00         4003.     Intramyocellular Lipids Mobilization in Elderly: Relationships with Physical Activity, Maximal Aerobic Capacity and Insulin Sensitivity

David M. Rouffet1,2, Rachida Fissoune1, Christophe Hautier3, Dominique Sappey-Marinier4, Martine Laville5, Danielle Ibarolla4, Monique Sothier5, Marie-France Monnet6, Michel Ovize6, Marc Bonnefoy7, Chris Boesch8, Emmanuelle Canet-Soulas1

1CREATIS LRMN, UMR CNRS #5220, INSERM U630, University of Lyon - Université Lyon 1, Lyon, Rhone-Alpes, France; 2Centre for Ageing, Rehabilitation Exercise & Sport, Victoria University , Melbourne, Victoria, Australia; 3CRIS EA647, University of Lyon - Université Lyon 1, France; 4CERMEP, University of Lyon - Université Lyon 1, France; 5CRNH, University of Lyon - Université Lyon 1, France; 6Unité de Rééducation Cardiaque, University of Lyon - Université Lyon 1, France; 7Service de Médecine Gériatrique, University of Lyon - Université Lyon 1, France; 8Dept.Clinical Research, University Bern, Switzerland

Epidemiological studies show that impairments of the insulin-stimulated glucose metabolism in skeletal muscle initiate type 2 diabetes’ apparition in elderly subjects. Repeating physical activities throughout entire life may positively affect insulin sensitivity by improving intracellular fat homeostasis in skeletal muscle. 1H nuclear magnetic resonance spectroscopy (1H-MRS) technique offers the possibility to study lipid metabolism by performing repeated and non invasive measurements of intramyocellular lipids (IMCL) content. The objective of this study was to determine if the exercise-induced IMCL mobilization is related to physical activity, maximal aerobic capacity and insulin sensitivity in elderly people.

14:30         4004.     Interrogation of Short T2 Components in Sclerotic Bone Metastases with Ultra Short TE MRI

Christina Messiou1, David J. Collins1, Matthew D. Robson2, Veronica A. Morgan1, Nandita M. deSouza1

1Cancer Research UK Clinical Magnetic Resonance Research Group, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, UK; 2OCMR, Oxford University, Oxford, Oxfordshire, UK

Our aim was to investigate the feasibility of UTE imaging of short T2 components in sclerotic bone metastases. We have optimised UTE MRI of the spine to return signal from short T2 components in sclerotic bone metastases. Careful coil selection and large FOV and matrix size can overcome artefacts from non-linearity of gradients although this can result in a time penalty. UTE has potential for quantitative assessment of sclerotic bone metastases but further measurements between 0.07 and 4.7ms are necessary to optimise TEs and remove effects of long T2 components.

15:00         4005.     Computed Diffusion Weighted Imaging (CDWI) for Improving Imaging Contrast

Matthew Blackledge1, Ben Wilton1, Christina Messiou1, Dow-Mu Koh1, Matin O. Leach1, David J. Collins1

1CR UK Clinical Magnetic Resonance Research Group, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, UK

Evidence is given that computed high b-value images based on ADC calculations present improved image quality over acquired images at the same high b-value. Two example cases are shown, the first demonstrating the improved SNR of computed over acquired b = 1400 s mm-2 images of iliac crest metastases and the second assessing the viability of extrapolating computed prostate images to b = 2000 s mm-2.

 


 
Advances in Abdominal MRI Methods
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 58

14:00         4006.     Parallel RF Transmission in Body MRI for Reduced Dielectric Shading, Improved B1 Homogeneity and Accelerated Imaging at 3.0T: Initial Clinical Experience in 40 Patients Using MultiTransmit

Winfried A. Willinek1, Juergen Gieseke1,2, Guido Kukuk1, Michael Nelles1, Roy König1, Magnus Andersson1, Daniel Thomas1, Nushin Morakkabati-Spitz1, Romhild Hoogeveen2, Christiane K. Kuhl1, Hans H. Schild1

1Department of Radiology, University of Bo nn, Bonn, Germany; 2Philips Healthcare

Electromagnetic wave propagation in tissue is known to cause dielectric resonance effects if the wavelength reaches the object dimension at higher field strength. Multiple transmit channels can provide better control of the RF field by allowing to send independent RF pulses yielding more uniform excitation and receive fields. The clinical usefulness of a parallel RF transmit system with patient-adaptive RF shimming and parallel transmission was tested in 40 patients for liver, pelvis and spine imaging at 3.0T. Parallel RF transmit body MRI allowed for reduced dielectric shading, improved B1 homogeneity and accelerated imaging at 3.0T in a routine clinical setup.

14:30         4007.     Irregular Respiratory Motion Correction in 3D T2w-TSE (PACE) Liver Imaging

Sang-Young Zho1, Jaeseok Park2, Dong-Hyun Kim1,2

1Electrical and Electronic Engineering, Yonsei University, Shinchon-Dong, Seoul, Korea; 2Radiology, Yonsei University, Shinchon-Dong, Seoul, Korea

irregular breahing during 3DFT T2w-TSE liver imaging cause motion artifact due to long echo-train length even with PACE technique. If we assume irregularity changes respiration period excluding cohghing and sighing, we can correct superior-infirior directional motion using navigator information before and after triggering. Navigator after triggering shows large variation.

15:00         4008.     VIBE with Projections Onto Convex Sets (POCS) for Abdominal Imaging

Agus Priatna1, Eric Hatfield2, Samuel Chang2, Wilhelm Horger3, Stephan Kannengiesser3, Vamsi Narra2

1R&D Collaborations, Siemens Medical Solutions USA, St Louis, MO, USA; 2Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, USA; 3MR Applications Development, Siemens AG Healthcare Sector, Erlangen, Germany

Abdominal imaging for critically ill patients requires a short breath-hold scan time. Volumetric Interpolated Breath-hold Examination (VIBE) is routinely used for the dynamic contrast enhanced studies for characterizing lesion in the abdominal organs such as the liver and the kidneys. To further reduce the scan time, phase partial Fourier is often employed. However, phase partial Fourier and echo asymmetry increase blurring in the in-plane view. In this abstract, phase correction with projection onto convex sets (POCS) is used with the VIBE sequence in order to reduce the blurring and maintain the image quality

15:30         4009.     Pediatric Abdominal Navigated T1-Weighted MRI

Shreyas S. Vasanawala1, Daniel Gene Church1, Yuji Iwadate2, Robert Herfkens1, Brian Andrew Hargreaves1, Anja C. Brau3

1Radiology, Stanford University, Stanford, CA, USA; 2ASL-Hino, GE Healthcare, Hino, Japan; 3ASL-West, GE Healthcare, Menlo Park, CA, USA

We explore navigation to decrease motion artifacts in pediatric abdominal T1-weighted imaging. An intermittent two-dimensional excitation pulse followed by a readout gradient was incorporated into our routine fat-suppressed 3D gradient echo sequence. Pediatric patients underwent the following protocol: immediate post-contrast suspended respiration acquisition, followed by free-breathing navigated and then free-breathing routine (non-navigated) acquisition. Images were graded for motion artifacts. Suspended respiration images had significantly better image quality than navigated free-breathing, whereas navigated free-breathing images had significantly better image quality than conventional free-breathing. The method may benefit patients who cannot suspend respiration.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 58

13:30         4010.     Intraindividual Comparison of Gadobenate Dimeglumine (MultiHance®) and Ferucarbotran (Resovist®) Enhanced MR Imaging of Hypervascular Liver Lesions

Guenther Schneider1, Wolfgang Loytved2, Luigi Grazioli3, Richard Semelka4, Gianni Morana5, Miles Andrew Kirchin6, Arno Buecker2, Peter Fries2

1University Hospital of Saarland, Homburg / Saar, Germany; 2University Hospital of Saarland, Germany; 3University of Brescia, Italy; 4University of North Carolina at Chapel Hill, USA; 5General Hospital Caì Foncello, Treviso, Italy; 6Bracco Imaging SpA, Milan, Italy

Gadobenate dimeglumine (MultiHance) and Ferucarbotran (Resovist) are MR contrast agents that can be used for both dynamic and delayed phase imaging of the liver. Whereas MultiHance is a gadolinium agent that undergoes partial uptake by functioning hepatocytes, Resovist is an iron oxide agent that undergoes uptake by Kupffer cells. The present study compared these two agents intra-individually for dynamic and delayed imaging in 43 patients with confirmed hypervascular focal liver lesions in a blinded off-site read. MultiHance was significantly superior to Resovist for lesion detection both when dynamic images were evaluated alone and when comparison was made of all available image sets.

14:00         4011.     Use of Iron Sensitive T2* MR Imaging as a Novel Method to Diagnose Hepatocellular Carcinoma

Andrew Dean Hardie1, Peter Romano1

1Radiology, Medical University of South Carolina, Charleston, SC, USA

Hepatic iron deposition is a common finding in cirrhosis and MRI has the ability to detect iron. As hepatocellular carcinoma (HCC) does not have the same degree of iron uptake as the liver, iron sensitive MR sequences allow visualization of HCC. We evaluated a novel method for identifying HCC with a breath-hold multi-echo gradient echo sequence using gadolinium enhanced images as the reference standard. On a per patient basis, the technique demonstrated 100% sensitivity and 78% sensitivity on a per lesion basis. This sequence could be used in patients contraindicated for gadolinium.

14:30         4012.     Can Gadolinium-Enhanced MRI Be Used for the Grading of Liver Fibrosis and Acute Hepatitis?

Thomas C. Lauenstein1,2, Khalil Salman2, Puneet Sharma2, Roger Moreira3, Diego R. Martin2

1Radiology, University Hospital Essen, Essen, Germany; 2Radiology, Emory University, Atlanta, GA, USA; 3Pathology, Emory University, Atlanta, GA, USA

We evaluated the accuracy of gadolinium-enhanced MRI for the quantification of cirrhosis and acute hepatic inflammation. 25 normal subjects, 25 patients with intermediate and 25 patients with severe cirrhosis were studied. Gadolinium enhanced T1w gradient echo sequences were acquired in arterial and late venous phases within 14 days of biopsy and histopathologic tissue analysis. MRI analysis for cirrhotic changes included the grading of reticular hyperintensity of liver tissue on the delayed phase images. Patchy enhancement patterns on the arterial phase images were evaluated for acute hepatic inflammation. An MRI based scoring for cirrhosis and acute hepatitis correlated well with histopathology.

15:00         4013.     Utility of Multiple-Echo Data Image Combination Sequence for SPIO-Enhanced T2*-Weighted MR Imaging of Liver MRI at 3.0 T System

Ji Soo Choi1, Myeong-Jin Kim1, Joo Hee Kim1, Jin-Young Choi1, Yong Eun Chung1

1Radiology, Severance Hospital, Seoul, Korea

At 3T MR system, SPIO)-enhanced liver MRI may have the theoretical advantage of high SNR and high liver to lesion contrast, because of stronger susceptibility effect compared with that at 1.5 T. On T2*-weighted gradient recalled echo (GRE) sequences essential for SPIO-enhanced liver MRI, positive effects of 3T on lesion-to-liver CNR were offset by the substantially reduced image quality, secondary to motion and susceptibility artifacts. MEDIC (multiple-echo data image combination) sequence can provides a potential solution by using a series of GRE images at different echo times. On MEDIC sequence, the combination of multiple echoes improves SNR. Receiver bandwidth can then be increased due to improved SNR. Consequently, T2* effects and impairment of the spatial resolution are reduced compared with conventional T2* GRE sequence. Although MEDIC was not superior to FISP for lesion detection, MEDIC showed significantly improved image quality compared with FISP in this study. At 3T system, MEDIC sequence can be a useful alternative sequence to replace FISP sequence for SPIO-enhanced MRI by improving overall image quality and decreasing flow artifact and undesired susceptibility artifacts.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 58

13:30         4014.     Determination of Optimal Liver-Lesion Contrast in LOW-TIDE B-SSFP Imaging

Neville Dali Gai1, Lawrence Yao1

1Radiology & Imaging Sciences, National Institutes of Health, Bethesda, MD, USA

LOW-TIDE is a magnetization preparation scheme for balanced steady-state free precession that provides T2 weighting (instead of T2/T1 weighting of b-SSFP sequences) and intrinsic fat suppression when used in conjunction with partial Fourier encoding along phase direction. It is particularly suitable for abdominal imaging. Contrast characteristics have a complex dependency on the number of 180 pulses and ramp down (to asymptotic final flip angle) pulses used. In this work, we investigate optimal contrast between liver and solid tumors through simulations. Predictions are corroborated with experimental measurements on patients with metastatic liver disease.

14:00         4015.     VIBE with Reversed Asymmetric Echo for Liver Imaging

Agus Priatna1, Eric Hatfield2, Samuel Chang2, Wilhelm Horger3, Stephan Kannengiesser3, Vamsi Narra2

1R&D Collaborations, Siemens Medical Solutions USA, St Louis, MO, USA; 2Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, USA; 3MR Applications Development, Siemens AG Healthcare Sector, Erlangen, Germany

Volumetric Interpolated Breath-hold Examination (VIBE) has been routinely used for dynamic contrast enhanced MR imaging of the body organs including the liver. In this article, we develop a technique using a reversed asymmetric acquisition in the readout direction such that the opposed phase TE can be acquired in a short TR while maintaining excellent fat suppression. This method significantly reduces the breath-hold time period which is essential for applications on severely ill patients in the clinical environment.

14:30         4016.     Reduction in Artifacts in the Liver at 3T Using a 3D T2-Weighted Variable Flip-Angle Sequence (SPACE)

Andrew Brian Rosenkrantz1, Jignesh M. Patel1, James S. Babb1, Pipps Storey1, Elizabeth M. Hecht1

1Radiology, New York University School of Medicine, New York, USA

A 3D T2-weighted variable flip-angle TSE sequence (SPACE) using a respiratory-navigated acquisition was performed of the liver at 3T in 20 patients. Compared with a 2D T2W TSE sequence, SPACE demonstrated significantly improved vessel sharpness, flow signal suppression, fat signal suppression, ghosting, pulsation, and motion artifact. There was a trend toward increased dielectic effect with SPACE. In a side by side comparison of the two sequences, two readers both had a slight preference for SPACE. There was no significant difference in SNR of the liver and kidney. We conclude that image quality was overall improved with SPACE.

15:00         4017.     Hepatic MR Imaging with 3D Gradient Echo: Linear Cartesian K-Space Ordering with Partial Scan Along Both Slice and Phase Direction

Kyung Ah Kim1, Myeong-Jin Kim1, Gwenael Herigault2, Young Eun Chung1

1Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; 2MR Clinical Scientist Body/Oncology, Philips Healthcare, Best, Netherlands

Conventional 3D GRE sequences utilize either one of centric-linear, radial or linear ordering of k-space with a fat suppression technique and partial scan technique along a slice direction. Recently, we introduce a enhanced 3D-GRE sequence, which adopted a linear ordering with half scan along both slice and phase directions, and matched turbo scan factor with the number of slices. Theoretically, this sequence has potential advantages of better signal-to-noised ratio, better tissue contrast on arterial phase, better fat suppression, and improved anatomic sharpness and image homogeneity. In this study, we compared conventional and enhanced 3D T1-weighted GRE sequences in terms of image quality and conspicuity of focal liver lesions.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 58

13:30         4018.     SPACE Vs. 3D TSE MRCP at 1.5T MRI with Regard to Difference of Echo Spacing

Satoru Morita1, Eiko Ueno1, Ai Masukawa1, Kazufumi Suzuki1, Haruhiko Machida1, Mikihiko Fujimura1, Shinya Kojima1, Masami Hirata1, Takahiro Ohnishi2, Kazuhiro Kitajima3, Yasushi Kaji3

1Department of Radiology, Tokyo Women's Medical University Medical Center East, Arakawa-ku, Tokyo, Japan; 2Application group, Siemens-Asahi Medical Technologies, Tokyo, Japan; 3Department of Radiology, Dokkyo University School of Medicine, Tochigi, Japan

SPACE sequence has recently been used to obtain high resolution 3D images at 3.0T MRI. This has the advantage that it reduces SAR by use of the variable flip angle. The other great advantage of SPACE is the shortening of echo spacing. However, this has not previously been focused on. This prospective study using 20 healthy volunteers quantitatively verified the superiority of SPACE MRCP to conventional 3D TSE MRCP at 1.5T MRI due to the shortening of echo spacing.

14:00         4019.     Determination of Optimal Fat Suppression in LOW-TIDE B-SSFP Imaging Using Eigenvalue Analysis

Neville Dali Gai1, Lawrence Yao1

1Radiology & Imaging Sciences, National Institutes of Health, Bethesda, MD, USA

LOW-TIDE is a preparation scheme for T2 weighting and intrinsic fat suppression with balanced SSFP imaging when partial Fourier encoding (PFE)along the phase direction is used. The PFE factor determines fat suppression (FS) and can change with scan parameters. Here, a semi-analytical method to determine optimal PFE factor for FS is described and implemented in pulse software to provide real-time update to the PFE factor based on scan parameters. The method is tested in abdominal imaging of three volunteers by changing the PFE factor around the optimal value. Measurements in kidney cortex and perirenal fat show the accuracy of the predicted optimal PFE factor.

14:30         4020.     Fatty Acid Composition of Subcutaneous Fat and Bone Marrow in Human Calf Is Affected by Diet and Exercise: an 1H-MRSI Study at 4T

Min-Hui Cui1,2, Jong Hee Hwang1,2, Vlad Tomuta2, CJ Segal-Isaacson2, Daniel T. Stein2

1Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, USA; 2Medicine, Albert Einstein College of Medicine, Bronx, NY, USA

High-quality in vivo proton NMR spectra from human calf adipose tissue and bone marrow can be obtained by using 1H-MRSI at 4T. This technique can effectively detect differences in fatty acid (FA) composition among subjects undergoing diet or exercise. Athletic subjects have a higher fraction of monounsaturated and lowest saturated content of FA compared to sedentary subjects. On the other hand, the diet and weight loss affect FA composition. The fraction of diunsaturated FA improved and that of saturated FA decreased after a low fat diet, as well as after moderate weight loss.

15:00         4021.     Estimation of Liver Iron Content with Spin-Echo Vs. Gradient-Echo Sequences

Arthur Peter Wunderlich1, Holger Cario2, Mathias Schmid3, Markus Juchems1

1Diagnostic and Interventional Radiology, Univ.-Clinic Ulm, Ulm, Baden-Württemberg, Germany; 2Pediatric Clinic, Univ.-Clinic Ulm, Ulm, Baden-Württemberg, Germany; 3Internal Hematology, Univ.-Clinic Ulm, Ulm, Baden-Württemberg, Germany

To compare the liver iron content (LIC) determined by different MR methods, we investigated 30 patients with both spin-echo (SE) and gradient echo (GRE) sequences. LIC was measured with two published methods. Both methods correlate moderately for low LIC. In the high LIC range, however, patients with LIC of 150 … 250 mmol/kg liver dry tissue derived from SE show LIC values of 250 … 300 mmol/kg determined with GRE. A possible explanation for this may be the highly inhomogeneous iron distribution in the liver. Although GRE generally tends to overestimate LIC, both methods are suitable for decisions concerning patient management.

 


 
Abdomen I
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 59

14:00         4022.     Location Matched Histological Validation of MRI Parameters Relating to Mural Crohn’s Disease Activity.

Shonit Punwani1, Manuel Rodriguez-Justo1,2, Enrico De Vita1, Alan Bainbridge2, Stuart Bloom2, Steve Halligan1,2, Stuart Taylor1,2

1University College London, London, UK; 2University College London Hospital, London, UK

Disease activity in Crohn's disease is monitored based on a combination of clinical scores, biochemical markers and imaging via endoscopy and radiology. However, limitations to the accuracy of these techniques are recognised. Specific findings on MRI have been proposed as accurate markers of inflammation, but have yet to be convincingly validated. The purpose of this study was to validate proposed MR imaging features of Crohn's disease activity against a robust precision matched histopathological reference standard.

14:30         4023.     Correlation Between Colonic Mural Apparent Diffusion Coefficient and Clinical/biochemical Markers of Inflammation in Acute Colitis

Shonit Punwani1, Rehana Hafeez2, Doug Pendse2, Alan Bainbridge2, Paul Boulos1, Steve Halligan1,2, Stuart Taylor1,2

1University College London, London, UK; 2University College London Hospital, London, UK

High mural T2 signal intensity has been previously reported to correlate with acute inflammation in the small bowel of patients with known inflammatory bowel disease. It is also possibly related to mucosal oedema. Diffusion weighted imaging is sensitive to changes in extra and intracellular water fractions. This study correlates colonic mural apparent diffusion coefficient measurements with clinical/biochemical markers of inflammation to determine whether ADC could potentially provide a non-ionising quantitative site specific assessment of colitis.

15:00         4024.     Staging of Gastric Cancer: A Comparative Study with 64-MDCT and 1.5 T MRI

Michele Anzidei1, Alessandro Napoli2, Beatrice Cavallo Marincola2, Fulvio Zaccagna2, Pier Luigi Di Paolo2, Daniel Geiger2, Chiara Zini2, Carlo Catalano2, Roberto Passariello2

1Scienze Radiologiche, Universita' di Roma "Sapienza", Rome, Italy, Italy; 2Radiological Sciences, Sapienza University of Rome, Rome, Italy, Italy

MRI and MDCT are both solid diagnostic modalities for the local staging of gastric cancer. Thirty patients with endoscopic diagnosis of gastric carcinoma underwent preoperative Gadobenate Dimeglumine-MRI and MDCT. In comparison with MDCT, MRI offers a slightly better performance in the differentiation of early stages of disease.

15:30         4025.     Characterization of the Effects of Different Classes of Anesthesia on Gut Motility in the Rat Small Intestine Using Dynamic MRI

Amit Ailiani1, Thomas Neuberger2, Gino Banco3, James Brasseur3, Nadine Smith1, Andrew Webb4

1Bioengineering, Penn State University, University Park, PA, USA; 2Huck Institute, Penn State University, USA; 3Mechanical Engineering, Penn State University; 4Radiology, Leiden University Medical Center, Leiden, Netherlands

Dynamic MRI and spatiotemporal analysis were used to characterize the differences in gut motility caused by isoflurane and inactin anesthesisa. Both give rise to peristalsis with a single frequency component, and segmental motions with two different frequency components. However, the periods of inactivity between gut motions is much longer for isoflurane than inactin, and the speed of propagation is twice as high for inactin as it is for isoflurane. These direct observations confirm previous indirectly measured parameters, and provide a platform for completely non-invasive assessment of gut motility using different anesthetic agents.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 59

13:30         4026.     Prospective Evaluation of the Value of Secretin in Magnetic Resonance Cholangiopancreaticography in Patients with Suspected Chronic Pancreatitis

Johannes T. Heverhagen1,2, Eric Schlaudraff1, Klaus J. Klose1

1Department of Diagnostic Radiology, Philipps University, Marburg, Germany; 2Department of Radiology, The Ohio State University, Columbus, OH, USA

The purpose of this study was to show and determine the positive effect of secretin in MRCP to improve the reliability of the diagnosis chronic pancreatitis. 62 patients with suspected chronic pancreatitis were prospectively included. Sensitivity and specificity for the diagnosis of chronic pancreatitis and the kappa-coefficient for the agreement between both observers were calculated for examinations before and after secretin application. ). After secretin application sensitivities, specificities and the agreement determined by the kappa-coefficient between the two investigators improved. Application of secretin increases sensitivity, specificity and inter-observer agreement for the diagnosis of chronic pancreatitis. Secretin-enhanced MRCP may therefore replace diagnostic ERCP.

14:00         4027.     MR Cholangiography in Patients with Biliary Complications After Liver Transplantation: Which Sequence Enables Diagnosis and Differentiation Best?

Sonja Kinner1, Alexander Dechêne2, Susanne C. Ladd1, Thomas Zöpf2, Guido Gerken2, Gerald Antoch1, Michael Forsting1, Thomas C. Lauenstein1

1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany; 2Department of Gastroenterology and Hepatology, University Hospital Essen, Essen, NRW, Germany

Biliary stenoses are common complications after liver transplantation. ERCP is actually the gold standard to evaluate the bile ducts and differentiate between stenoses of the anastomosis and strictures of the ducts due to ischemia. In our study we evaluated different MRC sequences concerning their ability to diagnose and differentiate biliary strictures. Our results showed that one sequence alone can not present the whole disease. Thus, a clinical protocol to diagnose and differentiate biliary strictures should comprehend different MRC sequences to be able to compete against ERCP.

14:30         4028.     Magnetic Resonance Cholangio-Pancreatography (MRCP) of Post-Transplant Ischaemic-Type Biliary Lesion ITBL: Which Is the Best Imaging Sequence?

Andreas Helck1, Christoph Johannes Zech1, Helmut Diepolder2, Wieland Sommer1, Maximilian F. Reiser1, Christian Glaser1, Karin A. Herrmann1

1Departement for Clinical Radiology, University of Munich/Campus Grosshadern, Munich, Bavaria, Germany; 2Departement for Internal Medicine II, University of Munich, Munich, Bavaria, Germany

Ischaemic-type biliary lesion ITBL represents a serious complication after liver transplantation with potentially disastrous outcome, sometimes requiring re-transplantation. Distinguishing ITBL from other types of post-transplant biliary strictures is crucial. Magnetic-Resonance-Cholangio-Pancreatography (MRCP) is well established as a non-invasive imaging modality for the post-transplant investigation of the biliary system. The value of the individual imaging sequence in the diagnosis of ITBL is less clear. In this study we could demonstrate, that high resolution 3D-TSE yields best results in detecting and correctly diagnosing ITBL in liver transplant patients. SSFSE is also highly effective in classifying the type of the stricture.

15:00         4029.     Breath-Held 3D Steady State Free Precession MRCP: Preliminary Experience and Comparison with Respiratory-Triggered 3D FRFSE

Christine U. Lee1, James F. Glockner1

1Radiology, Mayo Clinic, Rochester, MN, USA

Preliminary clinical experience and comparison of two MRCP techniques: breath-held 3D SSFP MRCP with respiratory-triggered 3D FRFSE MRCP

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 59

13:30         4030.     High-Resolution Contrast-Enhanced MR Angiography for the Assessment of Vascular Complications of Pancreas Transplantation: 1.5 T Versus 3T

Ahmed Mohamed Housseini1,2, Patrick T. Norton1, Ismaeel Mohammad Maged1,2, Ehab Ahmed Abdel-Gawad1,3, Timothy M. Schmitt4, Kenneth L. Brayman4, Hugo Bonatti4, Timothy L. Pruett4, Thomas E. Huerta1, Klaus D. Hagspiel1

1Department of Radiology, University of Virginia Health System, Charlottesville, VA, USA; 2Department of Radiology, Suez Canal University, Ismailia, Egypt; 3Department of Radiology, El Minya University, El Minya, Egypt; 4Department of Surgery, University of Virginia Health System, Charlottesville, VA, USA

MRA at 3T is considered superior to 1.5T, although for most vascular territories proof is still lacking. Fifty 3D CEMRAs (25 1.5T and 25 3T) were analyzed for signs of rejection, infarction or major vascular complications. For both techniques, overall angiographic correlation with MRI was excellent and agreed with final clinical diagnosis in all cases. There were no statistically significant differences between qualitative performance characteristics for 1.5T and 3T. Both are suitable for assessment of vascular anatomy of pancreas allografts. Despite gains in spatial resolution and signal to noise on 3T systems, this did not increase accuracy in our experience.

14:00         4031.     Evaluation of Low and High B-Values for the Differentiation Between Pancreatic Carcinoma and Chronic Pancreatitis Using Diffusion-Weighted Imaging

Miriam Klauss1, Andreas Lemke2, Katharina Grünberg2, Moritz N. Wente3, Hans-Ulrich Kauczor1, Stefan Delorme2, Lars Grenacher1, Bram Stieltjes2

1Interventionel and diagnostic Radiology, University Hospital, Heidelberg, Baden-Württemberg, Germany; 2DKFZ, Heidelberg; 3Universitiy Hospital, Heidelberg

We evaluated the value of different b-values to differentiate between pancreatic carcinoma and chronic pancreatitis using DWI. Nineteen patients received DWI (b= 25-800s/mm2). Histopathologically, 13 had pancreatic carcinoma and 6 chronic pancreatitis. We measured the ADC within the lesions for all b-values. The difference in ADC was tested using a Mann-Whitney-U-Test. The results showed significant differences between the ADCs of pancreatic carcinoma and chronic pancreatitis at low b-values (b=75, 100, 150 and 200). At higher b-values (>300), the differences did not reach significance. In conclusion, for the differentiation between pancreatic carcinoma and chronic pancreatitis, low b-values outperform high b-values.

14:30         4032.     Diagnosis of Chronic Pancreatitis with Secretin-Enhanced Diffusion-Weighted MR Imaging

Fatih M. Akisik1, Kumaresan Sandrasegaran1, Stuart Sherman2, Chen Lin1, Alex M. Aisen1

1Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; 2Medicine, Indiana University School of Medicine, Indianapolis, IN, USA

Pancreatic ADC obtained with DWI at 3.0T may aid in the diagnosis of chronic pancreatitis. ADC response to secretin administration does not reliably categorize the severity of chronic pancreatitis.

15:00         4033.     Autoimmune Pancreatitis: MRI Pattern Including Manganese Enhancement

Sebastian Feuerlein1, Andrik J. Aschoff1, Markus S. Juchems1, Hans-Juergen Brambs1, Andrea S. Ernst1

1Radiology, University of Ulm, Ulm, Germany, Germany

Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis based on an autoimmune inflammatory process. The purpose of this study was to describe MR imaging characteristics of AIP.

14:00         4034.     Diffusion-Weighted MR Imaging for the Diagnosis of Intra-Abdominal or Anal Fistula

Masatoshi Hori1, Aytekin Oto1, Sarah Orrin1, Kenji Suzuki1, Richard L. Baron1

1Department of Radiology, The University of Chicago, Chicago, IL, USA

An intra-abdominal or anal fistula is condition which extends from a diseased intestinal segment to another organ or to the skin. MRI is increasingly thought to be an accurate and non-invasive imaging technique for the diagnosis of intra-abdominal or anal fistula. The purpose of this study was to determine whether the additional use of diffusion-weighted imaging (DWI) improves detection of the disease. Our results showed that fistulae appear hyperintense on DWI. Confidence scores for lesions with DWI and T2-weighted images combined or those with Gd-enhanced images and T2-weighted images combined were statistically significantly greater than those with T2-weighted images alone.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 59

13:30         4035.     Optimization of Fat Suppression for 3.0T DWIBS

Tomohiko Horie1, Tesuo Ogino2, Isao Muro1, Taro Takahara3, Hisamoto Moriguchi1, Yutaka Imai1, Kagayaki Kuroda4, Marc Van Cauteren2

1Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan; 2Philips Healthcare Asia Pacific, Shinagawa, Tokyo, Japan; 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 4Tokai University, Hiratsuka, Kanagawa, Japan

Uniform fat signal suppression is often difficult to achieve in a 3.0 Tesla MR system. DWIBS is a new method of diffusion MRI that suppresses background signal. In DWIBS, residual fat signals due to incomplete fat signal suppression often considerably degrade quality of the images. Therefore, it is essential to improve fat signal suppression methods. We compared five fat suppression methods: STIR, SPAIR, Non preparation method (NP), STIR+SPAIR, and STIR+NP. Combination of two methods demonstrated better fat signal suppression than a single method. In our experiments, when STIR were used with NP, unambiguous fat suppression can be achieved.

14:30         4036.     The Evaluation of Diffusion Weighted MR Imaging for Perianal Fistulas

Takeshi Yoshizako1, Akihiko Wada1, Megumi Nakamura1, Ai Kobayashi1, Koji Uchida1, Shinji Hara1, Akihiko Matumura1, Shirou Ozaki1, Hajime Kitagaki1

1Radiology, Shimane University, Izumo, Shimane, Japan

In this study, we retrospectively evaluated the value of DWI to make recommendations for the use of MR imaging in assessing perianal fistulas.The FS-T2-WI was useful to detection of the location and spread of perianal fistula and abscess. Especially, the DWI was useful to suggestive to the degree of inflammation.

15:00         4037.     Focal Hepatic Lesion Detection and Discrimination of Benign Lesions and Malignant Lesions: T2-Weighted Imaging Versus Diffusion-Weighted Imaging

Dal Mo Yang1, Hyun Cheol Kim, Geon-Ho Jahng, Wook Jin

1Radiology, East-West Neo Medical Center, Kyung Hee University, Seoul, Korea

Diffusion-weighted MR imaging may be helpful for detection of malignant hepatic lesions such as hepatocellular carcinoma, metastasis, and intrahepatic cholangiocarcinoma. However, DW imaging has no additional benefit for differentiation of benign hepatic lesions from malignant hepatic lesions compared with T2-weighted imaging..

 


 
Abdomen II
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 60

14:00         4038.     Pancreatic Adenocarcinoma Enhancement Correlates with Histological Differentiation

Thomas C. Lauenstein1,2, Bobby Kalb2, Juan Sarmiento3, Khalil Salman2, Volkan Adsay4, Diego R. Martin2

1Radiology, University Hospital Essen, Essen, Germany; 2Radiology, Emory University, Atlanta, GA, USA; 3Surgery, Emory University, Atlanta, GA, USA; 4Pathology, Emory University, Atlanta, GA, USA

We aimed to determine whether the degree of enhancement of pancreatic adenocarcinoma visualized on arterial phase gadolinium-enhanced MRI correlates with the histopathological tumor grade. Thirty-nine patients with pancreatic adenocarcinoma had MRI within 14 days prior to tumor resection. Based on histological grading there were 12 poorly differentiated, 2 poorly-to-moderately differentiated, 22 moderately differentiated and 3 well-differentiated adenocarcinomas. There was agreement between the MRI arterial enhancement pattern and histology in 30 of the 39 cases. Although minor discordance was found in 9 of 39 cases, statistical analysis showed agreement between the degree of arterial enhancement on MRI and histological tumor differentiation.

14:30         4039.     Small (≤ 2 Cm) Enhancing Lesions Seen Only During the Hepatic Arterial Phase: Evaluation with Gadobenate Dimeglumine (Gd-BOPTA) Enhanced MR Imaging During the Hepatobiliary Phase

Michele Di Martino1, Daniele Marin1, Antonino Guerrisi1, Gianmaria De Filippis1, Francesca Galati1, Carlo Catalano1, Roberto Passariello1

1Radiological Sciences, University of Rome "Sapienza", Rome, Italy

Typical Imaging findings for a confident and reliable diagnosis of HCC at MR imaging include: on T2-w images, typical HCC shows high signal intensity to the background liver; during the arterial phase, the lesion is generally hyperintense due to the dominant arterial supply. By converse, HCC becomes hypointense to the surrounding liver during the portal venous and equilibrium phases. However, a substantial number of small (¡Ü 2 cm) can only be detected as hypervascular foci during the arterial phase that is, unfortunately, a nonspecific finding.The hepatobiliary phase of Gd-BOPTA MR imaging enables accurate diagnosis of benign HAPE-only nodules and HAPE-only HCCs

15:00         4040.     Hepatocellular Carcinoma in Liver Transplantation Candidates: Intraindividual Comparison of Gadobenate Dimeglumine (Gd-BOPTA) Enhanced MR Imaging and Multiphasic 64-Slice CT

Michele Di Martino1, Daniele Marin1, Antonino Guerrisi1, Gianmaria De Filippis1, Daniele Geiger1, Carlo Catalano1, Roberto Passariello1

1Radiological Sciences, University of Rome "Sapienza", Rome, Italy

Despite recent improvements in the spatial and temporal

15:30         4041.     MRI Correlates of Intratumoral Tissue Types Within Colorectal Liver Metastases: A High Resolution Fresh Ex-Vivo Radiologic Pathologic Correlation Study

Laurent Milot1, Maha Guindi2,3, Steven Gallinger4,5, Carol Anne Moulton4,5, Kristy Brock6, Laura Dawson6, Masoom A. Haider7,8

1Medical Imaging, Sunnybrook Health Science Center, Toronto, Ontario, Canada; 2Pathology, University Health Network, Toronto, Canada; 3Pathology, Mount Sinai Hospital, Toronto, Canada; 4General surgery, University Health Network, Toronto, Canada; 5General surgery, Mount Sinai Hospital, Toronto, Canada; 6Radiation Oncology, Princess Margaret Hospital, Toronto, Canada; 7Medical imaging, Princess Margaret Hospital, Toronto, Canada; 8Medical imaging, Mount Sinai Hospital, Toronto, Canada

Liver metastases exhibit a heterogenous structure with areas of necrosis, fibrosis and different malignant cell types. We prospectively performed high resolution MRI of the fresh ex vivo metastases of seven consecutive patient with qualitative and quantitative signal analysis of ROI defined on the pathology samples and superimposed on the MRI. Student t test was performed to assess significance of variations in signal from the different tissue types. Intra-acinar necrosis seen in colorectal metastases exhibits a specific high T1 signal and mixed T2 signal. This signal pattern is unusual for common benign liver lesions and may be helpful in the MRI diagnosis colorectal liver metastases.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 60

13:30         4042.     A T2* Magnetic Resonance Imaging Study of Pancreatic Iron Overload in Thalassemia Major, Thalassemia Intermedia and Thalasso-Drepanocytosis

Gennaro Restaino1, Massimiliano Missere1, Matteo Ciuffreda1, Eleonora Cucci1, Alessia Pepe2, Giuseppina Sallustio1

1Radiology, Catholic University of Sacred Heart, Campobasso, CB, Italy; 2MRI laboratory. Institute of Clinical Physiology,, Consiglio Nazionale delle Ricerche, Pisa, PI, Italy

Impairment of pancreatic function is a common complication in patients with thalassemia. Purpose: to evaluate a procedure of T2* assessment in the pancreas; to describe the T2* values of the pancreas in patients with thalassemia; to explore the correlation between pancreatic siderosis and hepatic and myocardial siderosis, diabetes, serum ferritin, and chelation. Methods: 37 thalassemic patients underwent singleslice multiecho T2* MRI in order to measure myocardial, liver and pancreatic T2*. Results: Pancreatic T2* measurement is feasible, simple, and reliable. Pancreatic siderosis doesn’t correlate with liver hemosiderosis, diabetic status or chelation treatment, but strongly correlates with myocardial siderosis and serum ferritin.

14:00         4043.     Metabolic Characterization of Primary Human Colorectal Cancers Using High Resolution Magic Angle Spinning 1H Magnetic Resonance Spectroscopy

Martial Piotto1,2, François-Marie Moussallieh3,4, Baudouin Dillmann4, Alessio Imperiale, Agnes Neuville, Cecile Brigand, Jean-Pierre Bellocq, Karim Elbayed, Izzie Namer

1Bruker Biospin, Wissembourg, France; 2Strasbourg University, Strasbourg, Strasbourg, France; 3University Hospitals of Strasbourg, Strasbourg, France; 4Strasbourg University, Strasbourg, France

Colorectal cancer is one of the most frequent and most lethal forms of cancer in the western world. The aim of this study is to characterize by 1H high resolution magic angle spinning NMR spectroscopy (HRMAS) the metabolic fingerprint of both tumoral and healthy tissue samples obtained from a cohort of patients affected by primary colorectal adenocarcinoma. By analyzing HRMAS data using multivariate statistical analysis (PLS-DA), the two types of tissues could be discriminated with a high level of confidence. The identification of the metabolites at the origin of this discrimination revealed that adenocarcinomas are richer in taurine, glutamate, aspartate and lactate whereas healthy tissues contain a higher amount of myo-inositol and β-glucose.

14:30         4044.     Detection and Quantification of D-Glucuronic Acid (GlcUA) in Human Bile by Using 1H MRS

Tedros Bezabeh1, Omkar B. Ijare1, Nils Albiin2, Urban Arnelo3, Bo Lindberg2, Ian CP Smith1

1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2Radiology, Karolinska Institutet, Stockholm, Sweden; 3Surgery, Karolinska Institutet, Stockholm, Sweden

Bilirubin is a major biliary pigment mostly present in conjugation with glucuronic acid as bilirubin diglucuronide. Bilirubin diglucuronide may be hydrolyzed in the presence of β-glucuronidase releasing free bilirubin and D-glucuronic acid into the bile. Bilirubin is reabsorbed into the body, but glucuronic acid is retained in the bile and could be analyzed. We report here a simple 1H MRS method for the detection and quantification of D-glucuronic acid in human bile. The bile samples from various patients with biliary obstruction (controls), chronic pancreatitis and pancreatic cancer have been analyzed by the proposed method. The study revealed elevated levels of D-glucuronic acid in pancreatic cancer patients, whereas D-glucuronic acid was absent or negligible in control and pancreatitis patients. This observation could have a diagnostic potential in the detection of pancreatic cancer.

15:00         4045.     Solid State 13C-NMR Analysis of Human Gall Bladder Stones<

K Jayalakshmi1, Kanchan Sonkar1, Anu Behari2, V. K. Kapoor2, Neeraj Sinha1

1Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2Department of Surgical Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

The natural abundance 13C high resolution solid-state nuclear magnetic resonance (13C-NMR) spectra of gall stones from patients with Chronic Cholecystitis (CC) (n=12), Xantho-Granulomatous Cholecystitis (XGC) (n = 5) and Gall Bladder Cancer (GBC) (n = 10) show micro-structural variations of these gall stones. Significant structural differences were observed in gall stones from GBC as compared to those from CC. Gall stones from XGC showed similar structure as that of CC. Structural variations observed in GBC stones was much larger than stones from other disease type.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 60

13:30         4046.     Quantitative Proton MR Spectroscopy as a Biomarker of Tumor Necrosis in the Rabbit VX2 Liver Tumor

Ihab R. Kamel1, Manon Buijs, Josephina Vossen, li Pan2, Nouha Salibi2, Eleni Liapi, Christine Lorenz2, Jean-Francois H. Geschwind

1Radiology, Johns Hopkins Hospital, Baltimore, MD, USA; 2Siemens Healthcare

The aim of our animal study was to compare metabolic (quantification of tumor choline concentration) MR imaging findings to percent necrosis at pathology in rabbits bearing VX2 liver tumors. In this study choline concentration showed a relatively high correlation with tumor necrosis on pathology (R = 0.78). Thus proton MR spectroscopy may be useful to assess tumor necrosis.

14:00         4047.     Prolonged Signal Decay in the Ablated Area After Radiofrequency Ablation in the Ferucarbotran-Administered Liver: A Basic Experimental Study for the Visualization of Ablative Margins in a Rabbit Model

Kensaku Mori1,2, Masayuki Yamaguchi2, Hirofumi Fujii2, Ryutaro Nakagami2,3, Toshihiro Furuta2,4, Manabu Minami1

1Department of Diagnostic and Interventional Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan; 2Functional Imaging Division, National Cancer Center East Hospital, Kashiwa, Chiba, Japan; 3Faculty of Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 4Department of Radiology, Graduate School of Medicine, University of Tokyo, Bunkyo, Tokyo, Japan

The assessment of ablative margins is critical to predict the local recurrence of malignant hepatic lesions after radiofrequency ablation (RFA). The following is a method to distinguish ablative margins from tumors and non-ablated hepatic tissue. We hypothesized that if RFA is performed on the ferucarbotran-administered liver, the signal decay of the ablated liver parenchyma will be prolonged because of impaired ferucarbotran clearance. After RFA, the ablated area appeared hypointense for 4 weeks in all 4 rabbits in the ferucarbotran group and in 1 of the 3 control rabbits. The mean contrast-to-noise ratios (CNRs) significantly differed between the 2 groups.

14:30         4048.     Non-Invasive and Quantitative Evaluation of Hepatic Fat Accumulation in Ob/ob Mice

Hyeonseung Lee1, quan-yu Cai1, Chulhyun Lee1, Ki-Nam Min2, Jong Kook Park2, Kyeong-Hoon Jeong2, Kwan Soo Hong1

1Magnetic resonance imaging team, Korea basic science institute, Ochang, Cheongwon-Gun, Chungcheongbuk-Do, Korea; 2Mazence, Suwon, Gyeonggi-Do, Korea

Alcoholic and nonalcoholic fatty liver are highly prevalent in human populations and may develop into steatohepatitis and in some cases into cirrhosis requiring liver transplantation. 1H magnetic resonance spectroscopy (MRS) has a high sensitivity for assessing the amount of hepatic fat content. We have isolated a novel compound, cryptotanshinone, from Salvia militorrhiza, which is an herb that is used extensively in Asian medicine and that is known to exert beneficial effects on the circulatory system. In this study, we demonstrated that in vivo non-invasively and quantitatively evaluate and monitor the hepatic fat accumulation in ob/ob mice depending on the treatment period/amount of cryptotanshinone using 1H-MRS technique.

15:00         4049.     Quantitative in Vivo Assessment of Hepatic Lipid Using High-Speed T2-Corrected Multi-Echo Spectroscopy

Puneet Sharma1, Nashiely Pineda2, Miriam Vos3, Qin Xu2, Xiaoping Hu2, Diego Martin1

1Radiology, Emory University, Atlanta, GA, USA; 2Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA; 3Hepatology, Children's Healthcare of Atlanta, Atlanta, GA, USA

In addition to susceptibility effects, a primary limitation of MRS for clinical use in the abdomen has been motion sensitivity and impractical scan duration. In this study, a rapid, breath-hold, single-voxel MRS technique was applied in vivo for the quantification of hepatic lipid (HL). The multi-echo technique provides T2-correction of %HL, which was shown to be significantly important due to measured variation in R2 of water and lipid. Clinical utility of the MRS method was established with reproducibility experiments, revealing robust in vivo %HL measurement within- and between imaging sessions.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 60

13:30         4050.     Balanced Steady-State Free Precession Abdominal Imaging Using Two-Point Dixon Fat/Water Decomposition

Ersin Bayram1, Vijay Nimbargi2, Ramesh Venkatesan2, Zachary Slavens1, Sabina Prato1, Manojkumar Saranathan3, Lloyd Estkowski1, Anthony Vu1

1MRI, GE Healthcare, Waukesha, WI, USA; 2GE Healthcare, Banglore, India; 3Applied Science Laboratory, GE Healthcare, Rochester, MN, USA

Fully balanced steady-state free precession techniques yield high signal in short scan times and have found applications in abdominal MRI for visualizing liver vasculature, biliary and small bowel imaging. Banding artifacts due to signal cancellations and robust fat suppression are the two challenges with these pulse sequences. Traditional fat suppression methods perform suboptimally due to their sensitivity to field inhomogeneities and compromise the steady state. We report a new technique that combines fully balanced steady-state free precession scan with a two-point Dixon fat-water reconstruction algorithm to generate high resolution fat-only and water-only image within breath-hold times.

14:00         4051.     Hepatic Vascular Flow Measurements by Phase Contrast MRI and Doppler Echography: A Comparative and Reproductibility Study

Thierry Yzet1, Roger Bouzerar2, Jean-Dominique Allart1, Fabien Demuynck1, Brice Robert1, Cécile Legallais3, Marc-Etienne Meyer4, Hervé Deramond1, Olivier Balédent4

1Radiology, CHU, Amiens, France; 2Medical imaging and biophysics, CHU , Amiens, France; 3Biomedical Engineering, UTC, Compiègne, France; 4Medical imaging and biophysics, CHU, Amiens, France

The purpose of this work is to compare Doppler echography with PC-MRI in order to appraise their reproducibility at the hepatic level in a population of 8 healthy subjects. They underwent Doppler echography and MRI flow measurements to explore the portal vein and the proper hepatic artery. 2 MRI and 2 Doppler examinations (1 year separation 2007/2008) were performed on the same subjects. At the hepatic artery level, the measurements’ deviations are more important than those recorded in the portal vein for both methods. The measurements’ variability using MRI was lesser with a correlation superior to Doppler data.

14:30         4052.     MR-Imaging Characteristics and Post-Therapeutic Morphologic Changes in Liver Metastases from Neuroendocrine Tumors

Wieland H. Sommer1, Christoph J. Zech1, Andreas Helck1, Maximilian F. Reiser1, Christine Schmid-Tannwald2, Karin A. Herrmann1

1Department of Clinical Radiology, University of Munich Hospitals, Grosshadern Campus, Munich, Germany; 2Department of Clinical Radiology, University of Munich Hospitals, Innenstadt Campus, Munich, Germany

Liver metastases of neuroendocrine tumors (NET) show MRI-characteristics, which differ from most other liver metastases. The aim of our study was to analyze treatment effects in MR-morphological terms, in PET imaging and in terms of perfusion, using a TWIST sequence.

15:00         4053.     Chemoembolization Follow-Up of Hepatocellular Carcinoma with MRI: Utility of Evaluating Enhancement Features on a 1 Month Follow-Up in Predicting Residual Disease After Therapy

Bobby Kalb1, Diego R. Martin2, Puneet Sharma, Abbas Chamsuddin

1Emory, Atlanta, GA, USA; 2Radiology, Emory, Atlanta, GA, USA

Determining therapeutic response after chemoembolization of HCC is important for guiding future therapy. Size measurements may be inaccurate in the early posttreatment setting. Evaluating vascular enhancement pattern of treated tumors may allow earlier determination of response. We evaluated 23 HCCs that have been treated with chemoembolization, and evaluated response on 1 and 6 month follow-up by qualitatively assessing the amount of residual enhancing tumor. Findings were compared with size changes at 6 months to correlate for residual disease. Evaluation of enhancement features of treated HCC on 1 month follow-up demonstrated good accuracy for assessment of residual disease after chemoembolization.

 


 
Abdominal & Whole-Body Diffusion
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 61

14:00         4054.     Effect of Hepatic Iron Deposition on DWI Measurements in Liver Cirrhosis

Hersh Chandarana1, Kinh Gian Do1, Ely Felker1, Cristina Hajdu2, Jens Jensen1, Bachir Taouli1

1Radiology, NYU Medical Center, New York, NY, USA; 2Pathology, NYU Medical Center, New York, NY, USA

We assessed the effect of hepatic iron deposition on liver signal intensity and apparent diffusion coefficient on diffusion-weighted images in cirrhotic patients. Our preliminary results show that severe iron deposition significantly lowers liver signal intensity on DWI for b0 and b500, and also decreases apparent diffusion coefficient (ADC) without reaching significance. The effect of hepatic iron deposition should be taken into account when using ADC for the diagnosis of liver fibrosis/cirrhosis.

15:00         4055.     Hepatocellular Carcinoma (HCC) with Portal Venous Tumor Thrombosis (PVTT) Response to Yttrium-90 Radioembolizaion Evaluated by Functional MRI

Yi Wang1, Robert J. Mccarthy2, Paul Nikolaidis3, Vahid Yaghmai3, Laura Merrick3, Andrew Larson3, Reed Omary3, Robert Lewandowski3, Riad Salem3, Frank H. Miller3

1Radiology , Northwestern University , Chicago , IL, USA; 2Anesthesia, Northwestern University, USA; 3Radiology, Northwestern University, Chicago, IL, USA

We assessed DWI compared with contrast-enhanced MR in the evaluation of early HCC and PVTT response to 90Y radioembolization. ADC and percentage enhancement of tumor and thrombosis were calculated in 25 patients. AFP, tumor size, change in percentage necrosis and follow-up were used as combined reference standards. ADC of tumor increased from baseline 1.42 (×10-3mm2/s) to 1.65 after treatment (p<0.05) and ADC of PVTT also increased from 1.29 to 1.54 (p<0.05). Based on reference standards, ADC change was significantly better to predict tumor and thrombosis response to treatment compared to percentage enhancement which was not helpful for early response. <

15:30         4056.     Detection of Hepatocellular Carcinoma in Pre-Liver Transplant Patients: Diagnostic Performance of DWI Compared to Gadolinium-Enhanced Imaging

Mi-Suk Park1, Jignesh Patel1, Sooah Kim1, Kinh Gian Do1, Leonid Drozhinin1, Lorenzo Mannelli1, Bachir Taouli1

1Radiology, NYU Medical Center, New York, NY, USA

In this study, we compared the diagnostic performance of DWI vs. gadolinium-enhanced MRI for the detection of hepatocellular carcinoma (HCC) in cirrhotic patients before liver transplantation. DWI was found to have overall lower sensitivity per patient and per lesion, with however better specificity than Gd-enhanced images, due to the non visualization of arterio-portal shunts. The combination of DWI with Gd-enhanced images may improve the specificity of Gd-enhanced imaging for HCC detection.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 61

13:30         4057.     Whole Body MRI for Tumor Staging in Patients with Renal Cell Carcinoma

Bernd B. Frericks1, Bernhard C. Meyer1, Alexander Huppertz2, Karl-Juergen Wolf1, Frank K. Wacker1,3

1Dept. of Radiology and Nuclear Medicine, Charité, Campus Benjamin Franklin, Berlin, Germany; 2Charité - Siemens, Imaging Science Institute, Berlin, Germany; 3Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Aim of this study was to evaluate the diagnostic accuracy of whole-body MR versus MDCT for staging of patients with renal cell carcinoma (RCC). Nineteen patients were examined in MDCT and in a 1.5T whole-body MR using routine imaging sequences. As compared to the reference standard, MR was comparable to MDCT for local tumor staging; STIR imaging alone was equal for N-staging. For the detection of hepatic metastases 3D-T1-GRE and T2w-TSE were superior to MDCT. For the detection of pulmonary metastases CT was slightly superior to STIR imaging. Dedicated whole-body MR enables accurate staging of patients with RCC.

14:30         4058.     Quantitative Analysis for Diffusion-Weighted and Superparamagnetic Iron Oxide Enhanced Magnetic Resonance Imaging in Patients with Chronic Hepatitis C: Correlation with Pathologic Fibrosis and Inflammatory Scores and Clinical Severity

Kiminori Fujimoto1,2, Tatsuyuki Tonan1, Shuji Nagata1, Sanae Azuma1, Osamu Nakashima3, Masayoshi Kage3, Takumi Kawaguchi4, Naofumi Hayabuchi1, Koji Okuda5, Takeshi Johkoh6

1Department of Radiology, Kurume University School of Medicine, Kurume, Fukuoka, Japan; 2Center for Diagnostic Imaging, Kurume University Hospital, Kurume, Fukuoka, Japan; 3Department of Pathology, Kurume University School of Medicine, Kurume, Japan; 4Department of Medicine, Kurume University School of Medicine, Kurume, Japan; 5Department of Surgery, Kurume University School of Medicine, Kurume, Japan; 6Department of Radiology, Kinki Central Hospital, Itami, Japan

The aim of study was to evaluate mean of region-of-interest and volume histogram analysis of signal intensities obtained by diffusion-weighted (DW)-MRI and superparamagnetic iron oxide (SPIO)-MRI for predicting the histopathologic liver fibrosis and inflammation scores and clinical severity. The study included 34 patients with chronic hepatitis C and 9 patients without hepatic dysfunction were retrospectively evaluated. The quantitative analysis of ADC values (DW-MRI) and reduction percentage of liver-to-muscle signal intensity ratio (SPIO-MRI) is helpful in predicting the histopathologic liver fibrosis as well as clinical severity in patients with chronic hepatitis.

14:00         4059.     Multi-Station Multi-Sequence Approach for Whole-Body Diffusion-Weighted Imaging

Yeji Han1, Sandra Huff1, Jürgen Hennig1, Ute Ludwig1

1Medical Physics, Dept. Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany

Recent report on wbDWI shows images acquired with body coils because surface coils result in significant respiratory artifact and the patients have to suffer from the weights of the surface coils. However, surface coils can generate better images for certain regions. Thus, we propose a method to employ the advantages of both the body and the surface coils to effectively obtain wbDWI using multi-station approach. In order to shorten the imaging time with body coils, an EPI reconstruction method is also proposed. The proposed method together with STIR-DWEPI sequence should produce good quality images with sufficiently suppressed fat signals.

14:30         4060.     A Combined Whole Body Diffusion- And Continous Table Movement STIR-Protocol for the Assessment of Fever of Unknown Origin (FUO): First Results

Sabine Weckbach1, Henrik J. Michaely1, Dietmar J. Dinter, Stefan O. Schoenberg2

1Department of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Mannheim, Germany; 2Department of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Mannheim, Mannheim, Germany

The purpose was to evaluate WB-MRI using DWI and continuous table movement (CTM) STIR sequences as a new modality for the workup of FUO without radiation exposure and less effort compared to scintigraphy. 6 patients with FUO were examined at 3 T using a combined protocol with coronal WB diffusion-weighted sequences (EPI-SpinEcho), coronal WB CTM STIR sequences and axial contrast-enhanced T1-weighted GRE (VIBE)-sequences as reference. In 5 patients pyogenic foci were detected. The first results using WB-DWI and CTM STIR-sequences are promising for the workup of FUO. The combined WB-DWI and CTM STIR protocol might replace leucocyte scintigraphy as diagnostic standard of reference in the future.

15:00         4061.     Whole-Body MRI at 1.5 and 3 Tesla Compared to FDG-PET-CT for the Detection of Tumor Recurrence in Patients with Colorectal Cancer

Gerwin P. Schmidt1, Andrea Baur-Melnyk1, Alexander Haug2, Becker Chistoph1, Reinhold Tiling2, Maximilian F. Reiser1, Karin Herrmann1

1Institute for Clinical Radiology, University Hospitals Munich, Munich, Germany; 2Department of Nuclear Medicine, University Hospitals Munich, Munich, Germany

FDG-PET-CT is the method of choice for integrated tumor imaging in the follow-up of colorectal cancer, especially for the diagnosis of lymph node metastases. WB-MRI is useful for the detection of organ metastases, especially to the liver, bone and brain. WB-MRI at 3 Tesla is feasible and provides further overall scan time reduction at constant image resolution.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 61

13:30         4062.     Early Assessing Tumor Response to Transarterial Chemoembolization by Diffusion-Weighted Imaging: Selection of the Optimal B Factor

Zhaoxia Jiang1, Weijun Peng1

1Department of Radiology, Affiliated Cancer Hospital of Fudan University, Shanghai, China

Diffusion-weighted imaging has been used to monitor hepatic carcinoma response after therapy in many studies. However, there are considerable discrepancies in the selection of b values. In this study, we compared different b-value DWI in evaluation of hepatic tumor necrosis after TACE in rabbits to explore the optimal b value. Our results suggest that high b-value DWI was more sensitive for early detection of tumor necrosis. However, the image quality diminished with increasing b value especially on b2000 DWI. These results demonstrate an intermediate b value (ie, 1000s/mm2) may provide optimal visualization.

14:00         4063.     Accuracy of Diffusion-Weighted Imaging for the Detection of Viable Tumor After Local Treatment of Hepatocellular Carcinoma in Cirrhotic Patients

Sung Eun Rha1, Young Joon Lee1, Soon Nam Oh1, Seung Eun Jung1, You Sung Kim1, Jae Young Byun1

1Department of Radiology, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea

Although the sensitivity and negative predictive value of DW imaging for the detection of perilesional viable tumor after local treatment of HCCs in cirrhotic patients were better than those of conventional contrast-enhanced MR imaging, the accuracy of diffusion weighted imaging alone is not good as conventional contrast-enhanced MR images. DW imaging can be used to improve the detection of perilesional viable tumor, in association with conventional MR images.

14:30         4064.     Diagnostic Value of Normalized Liver ADC Using the Spleen as a Reference for the Diagnosis of Cirrhosis

Kinh Gian Do1, Hersh Chandarana1, Cristina Hajdu2, Ruliang Xu2, Bachir Taouli1

1Radiology, NYU Medical Center, New York, NY, USA; 2Pathology, NYU Medical Center, New York, NY, USA

Liver ADC and relative ADC (normalized by spleen ADC) were calculated in 19 patients who underwent liver biopsy or transplantation. ADC was calculated using breath hold DWI with b-values of 0-50-500 sec/mm2. Relative ADC was superior to absolute liver ADC for the distinction between cirrhotic and non-cirrhotic livers.

15:00         4065.     Apparent Diffusion Coefficient of Hepatocellular Carcinoma.

Paul Thomas Stanton1, Fred Kelcz2

1Radiology, University of Wisconsin, Madison, WI, USA; 2University of Wisconsin, USA

Our study was performed to characterize proven hepatocellular carcinomas with respect to apparent diffusion coefficient (ADC) and to establish any links between the ADC and pathologic grade of tumor.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 61

13:30         4066.     Echo Planar Diffusion-Weighted MRI of the Abdomen and Pelvis: Comparison of Free-Breathing Monopolar and Bipolar Spin-Echo Sequences in Image Quality and Geometric Distortions

Stavroula Kyriazi1, Veronica A. Morgan2, David J. Collins2, Nandita M. deSouza2

1Cancer Research UK Clinical Magnetic Resonance Group, Institute of Cancer Research and Royal Marsden NHS Foundation Trust , Sutton, Surrey, UK; 2Cancer Research UK Clinical Magnetic Resonance Group, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Surrey, UK

Single-shot spin-echo echo planar diffusion weighting imaging (ssEPI-DWI)suffers from geometric distortion due to eddy currents generated by the strong gradient pulses. The application of a bipolar technique with alternating polarity diffusion sensitising gradients has been proposed to counteract these magnetic field inhomogeneities. In this study on seven healthy volunteers we compare the monopolar (conventional Steskal and Tanner) with the bipolar sequence in free-breathing abdominal and pelvic diffusion imaging, in terms od signal-to-noise ratio (SNR), apparent diffusion coefficient values (ADC), efficiency of fat saturation, and visual image quality. Our results suggest that despite their lower SNR, bipolar acquisitions provide improved image quality primarily due to reduced sensitivity to distortion artifacts.

14:00         4067.     Reproducibility of ADC Measurements of Abdominal Organs at 1.5T and 3T

Andrew Rosenkrantz1, Marcel Oei1, Hersh Chandarana1, Bachir Taouli1

1NYU Medical Center, New York, NY, USA

Reproducibility of ADC (apparent diffusion coefficient) measurements is extremely important for the design of drug trials and prospective protocols involving DWI in the abdomen. Three volunteers underwent baseline and follow-up abdominal DWI at both 1.5T and 3T, and coefficients of variation (CV) of ADC of abdominal organs were calculated for both field strengths. ADC of kidney, pancreas, and spleen showed excellent reproducibility at 1.5T and 3T, but reproducibility of liver ADC was moderate at both field strengths. There was no significant difference in CV of ADC between field strengths. Our preliminary data supports use of serial ADC measurements in the abdomen, with some caution warranted when applied in the liver.

14:30         4068.     Respiratory Motion Artefact Reduction on Abdominal DWI: Simultaneous Use of Dual Bipolar Diffusion Gradient and Navigator Slice Tracking

Tetsuo Ogino1, Tomohiko Horie2, Isao Muro2, Taro Takahara3, Marc Van Cauteren4

1Philips Electronics Japan, LTD, Minato-ku, Tokyo, Japan; 2Department of Radiology, Tokai University, Isehara, Kanagawa, Japan; 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 4MR Clinical Science, Philips Healthcare, MInato-ku, Tokyo, Japan

In upper abdominal region, respiratory motion affects image quality of DWI. Motion of the diaphragm causes through-slice tissue motion resulting in blurring and misregistration of adjacent slices. Recently, slice tracking with respiratory navigator was proposed to minimize these artefacts. Another major issue with abdominal DWI is signal loss in soft tissues. It was suggested that voxel deformation due to respiratory and cardiac motion under MPG induces intra-voxel phase dispersion that causes the signal loss. We evaluated the efficiency of dual bipolar MPG on abdominal DWI as a counteraction of this effect, and also combined this method with slice tracking.

15:00         4069.     Pitfalls in Abdominal Diffusion-Weighted Imaging – How Specific Is Restricted Water Diffusion for Malignancy?

Sebastian Feuerlein1, Sandra Pauls1, Markus S. Juchems1, Hans-Juergen Brambs1, Andrea S. Ernst1

1Radiology, University of Ulm, Ulm, Germany, Germany

As DWI is increasingly implemented into routine protocols of abdominal MRI, positive findings both in expected as in unexpected locations become more common. The aim of our study was to investigate the potential pitfalls of false positive findings in abdominal DWI by identifying benign lesions that have restricted diffusion. Restricted diffusion is generally considered to be associated with malignant tumors as a result of high cellularity. However, when interpreting DW images, it should be kept in mind that a number of benign lesions, as high as 22% in our cohort, could demonstrate restricted diffusion, thus mimicking malignancy.

 


 
Contrast Enhanced Hepatobiliary Imaging
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 62

14:00         4070.     Gd-EOB-DTPA Enhanced MR Imaging Findings of Non-Diffuse Fatty Change of the Liver

Atsushi Higaki1, Akira Yamamoto1, Tsutomu Tamada1, Hiroki Higashi1, Tomohiro Sato1, Akihiko kanki1, Katsuyoshi Ito1

1Kawasaki Medical School, Kurashiki, Okayama, Japan

To evaluate the difference in enhancement effects of the liver between area of fatty change and area of non-fatty change at gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced MR imaging to clarify whether the presence of fatty infiltration affected the liver uptake of Gd-EOB-DTPA. Our results showed that the presence of fatty infiltration of the liver did not affect the hepatic contrast enhancement effects of Gd-EOB-DTPA in both vascular and hepatocellular phases. This fact indicated that the hepatic function for the uptake of Gd-EOB-DTPA can be preserved in the area of fatty change of the liver.

14:30         4071.     High Resolution Double Arterial Phase Hepatic MR Imaging Using Adaptive 2D Centric View Ordering: Initial Clinical Experience

Russell N. Low1,2, Ersin Bayram3, Neeraj Panchal1,2, Lloyd Estowski3

1Sharp and Children's MRI Center, San Diego, CA, USA; 2San Diego Imaging Medical Group, San Diego, CA, USA; 3General Electric HealthCare, Waukesha, WI, USA

Prior techniques for multiple arterial phase hepatic imaging require lower resolution and increased slice thickness combined with SENSE or keyhole imaging techniques to accelerate image acquisition. Modified-LAVA sequence enables fast abdominal MRI with high spatial and temporal resolution. Modified-LAVA supports a novel adaptive 2D centric view ordering, efficient sampling pattern with 2D auto-calibrated acceleration and partial Fourier acquisition to achieve faster scanning. Double arterial phase MRI can be performed with identical slice thickness, spatial resolution, and anatomic coverage as is used in single phase imaging. Multiple arterial phases simplify bolus timing and provide information to improve tumor detection and characterization.

15:00         4072.     Quintuple Arterial Phase Gd-EOB-DTPA Enhanced Dynamic MR Imaging with Interleaved Stochastic Trajectories for Hepatocellular Carcinoma

Satoru Kitano1, Nagaaki Marugami1, Junko Takahama1, Aya Hashimoto1, toshiaki Taoka1, shinji Hirohashi2, kimihiko Kichikawa1

1Department of Radiology, Nara Medical University, kashihara, Nara, Japan; 2Department of Radiology, osaka gyoumeikan hospital, osaka, Japan

Gd-EOB-DTPA is a new hepatobiliary MRI contrast agent, detection and characterization of liver tumors. This compound is taken up by the hepatocytes and is equally excreted renal and biliary in humans. Dynamic and accumulation phase imaging can also be performed after bolus injection of Gd-EOB-DTPA. Time-resolved MR angiography (MRA) offers the combined advantage of large anatomic coverage and hemodynamic flow information. We applied parallel imaging and time-resolved imaging with stochastic trajectories (TWIST) to perform Gd-EOB-DTPA enhanced dynamic MRI for hepatocellular carcinoma. We obtained quintuple arterial phase dynamic MR imaging and time resolved MR angiography simultaneously. The purpose of this study was to describe and validate the use of time resolved Gd-EOB-DTPA enhanced MRI for the noninvasive assessment of hemodynamics and hepatocytes functional information of hypervascular hepatocellular carcinoma.

15:30         4073.     Gadolinium-Enhanced Multi-Phasic MR Imaging of the Liver and Pancreas at 3.0 Tesla: Qualitative and Quantitative Comparison with 1.5 Tesla

Tonsok Kim1, Masatoshi Hori1, Hiromitsu Onishi1, Yasuhiro Nakaya1, Atsushi Nakamoto1, Mitsuaki Tatsumi1, Kaname Tomoda1, Hironobu Nakamura1

1Dept. of Radiology, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan

Gadolinium-enhanced multi-phasic MR imaging using 3D gradient echo sequence is clinically important for the diagnosis of hepatic and pancreatic disease. We compared tissue contrast and image quality for gadolinium-enhanced multi-phasic MR imaging of the liver and pancreas at 3.0 T with those at 1.5 T. Tissue contrast for gadolinium-enhanced multi-phasic MR imaging of the liver and pancreas at 3.0 T was equivalent to that at 1.5 T, but image quality for 3.0 T tended to be worse than that for 1.5 T.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 62

13:30         4074.     MR Cholangiography with Gd-EOB-DTPA: Biliary Enhancement Dynamics in Clinical Patients

Hiromitsu Onishi1, Tonsok Kim1, Masatoshi Hori1, Takamichi Murakami2, Mitsuaki Tatsumi1, Yasuhiro Nakaya1, Atsushi Nakamoto1, Takahiro Tsuboyama1, Kaname Tomoda1, Hironobu Nakamura1

1Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; 2Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka, Japan

The aim of the present work was to evaluate the biliary enhancement dynamics of Gd-EOB-DTPA at MR cholangiography in clinical patients. Consecutive 22 patients suspected of having liver tumors underwent Gd-EOB-DTPA-enhanced MR examination. The delayed (hepatobiliary) phases were acquired 10, 20 and 40 minutes after the injection of Gd-EOB-DTPA using a three-dimensional gradient-echo sequence. In the most cases, a 20-minutes delay after the injection was considered sufficient for the MR cholangiography with Gd-EOB-DTPA. However, a 40-minutes delay was needed in some cases, particularly in the patients with hyperbilirubinemia and improved the delineation of the gall bladder.

14:00         4075.     Kinetic Analysis of Gd-EOB Uptake by Hepatocytes with Gd-EOB-Enhanced Dynamic MR Imaging

Hiromitsu Onishi1, Tonsok Kim1, Masatoshi Hori1, Takamichi Murakami2, Takahiro Tsuboyama1, Mitsuaki Tatsumi1, Atsushi Nakamoto1, Yasuhiro Nakaya1, Kaname Tomoda1, Hironobu Nakamura1

1Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; 2Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka, Japan

The purpose of the present study was to analyze the kinetics in the uptake of Gd-EOB by the hepatocytes by using a Michaelis-Menten model. Uptake rate and concentration of Gd-EOB was estimated from Gd-EOB-enhanced dynamic MR imaging data. To evaluate whether the relationship between the uptake rate and the Gd-EOB concentration obey Michaelis-Menten kinetics, an Eadie-Hofstee Plot was analyzed. A Hanes-Woolf Plot was also generated to obtain an apparent Michaelis constant.

14:30         4076.     Contrast-Enhanced MR Cholangiography with Gd-EOB-DTPA: Visualization of the Biliary Ducts in Comparison with HASTE MR Cholangiography

Yoshihiko Fukukura1, Takuro Kamiyama1, Koji Takumi1, Toshikazu Shindo1, Yuichi Kumagai1, Masayuki Nakajo1

1Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan

The purpose of this study was to assess the quality of biliary duct visualization using Gd-EOB-DTPA-enhanced magnetic resonance cholangiography (EOB-MRC) compared with half-Fourier acquisition single-shot turbo spin-echo magnetic resonance cholangiography (HASTE-MRC).In all patients, EOB-MRC showed significantly improved visualization of cystic duct (average score of three readers 3.43 vs. 3.01; P<0.05), and first (average score of three readers 4.12 vs. 3.75; P<0.005) and second division ducts (average score of three readers 3.00 vs. 2.51; P<0.0005) in comparison with HASTE-MRC. In patients with liver cirrhosis, there was no significant difference between EOB-MRC and HASTE-MRC in the grade of visualization of cystic duct, and first and second division ducts. These results suggest that EOB-MRC may be more useful in the evaluation of cystic duct, right and left hepatic duct, and second division ducts compared with HASTE-MRC in patients with normal liver function.

15:00         4077.     Comparison of Hepatic Enhancement and Tumor-To-Liver Contrast at Gd-EOB-DTPA Enhanced MR Imaging Between 1.5 T and 3.0 T

Tonsok Kim1, Masatoshi Hori1, Hiromitsu Onishi1, Yasuhiro Nakaya1, Atsushi Nakamoto1, Takahiro Tsuboyama1, Mitsuaki Tatsumi1, Kaname Tomoda1, Hironobu Nakamura1

1Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan

We compared hepatic enhancement and tumor-to-liver contrast at Gd-EOB-DTPA enhanced MR imaging between 1.5 T and 3.0 T. This study included 89 patients who underwent Gd-EOB-DTPA enhanced MRI for the evaluation of liver tumors. Liver-to-muscle signal intensity (SI) ratio, tumor-to-liver SI ratio, and conspicuity of liver tumors on Gd-EOB-DTPA enhanced MR imaging were compared between 1.5 T and 3.0 T Enhancement of liver parenchyma and tumor-to-liver contrast on Gd-EOB-DTPA enhanced MR images at 3.0 T were similar to those at 1.5 T.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 62

13:30         4078.     The Usefulness of Gadoxetic Acid (Gd-EOB-DTPA)-Enhanced MRI for Follow-Up Study in Patients of Malignant Hepatic Tumors Performed RF Ablation: Correlated with Four-Phase MDCT

Jung-Hee Yoon1,2, Eun-Joo Lee2, Seong-Sook Cha2, Sang-Suk Han2, Suk-Jin Choi2, Oh-Whan Park2, Yeon-Jae Lee3, Seong-Jae Park3

1Department of Radiology, Liver Imaging Research Group, UCSD Medical center, Hillcrest, San Diego, CA, USA; 2Department of Radiology, Busan Paik Hospital, Inje University, College of Medicine, Busan, Korea; 3Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea

Newly developed liver specific MR contrast agent, Gadoxetic acid (Gd-EOB-DTPA)! We expected that Gadoxetic acid should suggest more improved assessment of the ablative margin relative to the tumor margin in cases of RF ablation.

14:00         4079.     Optimization of Primovist-Enhanced MR Imaging Protocol

Akihiro Tanimoto1, Akihisa Ueno1, Shigeo Okuda1

1Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan

To optimize Gd-EOB-DTPA-enhanced MR imaging protocol in the diagnosis of hepatic tumors. We analyzed the timing of the dynamic phase, hepatocyte phase and diffusion weighted imaging (DWI). In normal bilirubin level, imaging at 10 minutes was comparable to 20 minutes. In abnormal bilirubin level, no significant difference of CNR was found between 15 minutes and 20 minutes. Gd-EOB-DTPA did not affect the quality of DWI. @ Optimized protocol offered the shortening of Primovist-enhanced MR examination time without the impairment of diagnostic performance.

14:30         4080.     Dynamic Contrast-Enhanced MR Imaging of the Abdominal Solid Organ and the Major Vessel: Comparison of the Enhancement Effect Between Gd-EOB-DTPA and Gd-DTPA

Tsutomu Tamada1, Katsuyoshi Ito1, Hiroki Higashi1, Takenori Yamashita1, Teruki Sone1, Shigeru Watanabe1, Daigo Tanimoto1, Akihiko Kanki1, Akiyuki Torigoe1

1Dept. of Radiology, Kawasaski Medical School, Kurashiki, Okayama, Japan

We evaluated the difference in the enhancement effect of the abdominal solid organ and the major vessel on DCE-MRI obtained with Gd-EOB-DTPA and Gd-DTPA. The relative enhancement (RE) of the abdominal solid organ including liver, and aorta at arterial-phase as well as the RE of portal vein and IVC at portal-phase in the Gd-EOB-DTPA images were significantly lower than those in the Gd-DTPA images. Conversely, the RE of liver at equilibrium-phase was significantly higher in Gd-EOB-DTPA than in Gd-DTPA. When using Gd-EOB-DTPA in the DCE-MRI, differences of the enhancement effect and the enhancement pattern of solid organs with Gd-DTPA need to be considered.

15:00         4081.     T2-Weighted MR Imaging of the Liver: Evaluation of the Effect in Signal Intensity After Gd-EOB-DTPA Enhancement

Tsutomu Tamada1, Katsuyoshi Ito1, Hiroki Higashi1, Teruki Sone1, Akira Yamamoto1, Naoto Egashira1, Tomohiro Sato1, Fuyuki Tanaka1, Atsushi Higaki1

1Dept. of Radiology, Kawasaski Medical School, Kurashiki, Okayama, Japan

We evaluated the effect of Gd-EOB-DTPA on T2-weighted MR imaging of the liver parenchyma. Gd-EOB-DTPA had visually little impact on enhanced T2-weighted MR images obtained at 4 minutes after administration although hepatic vessels were slightly enhanced. T2-weighted MR imaging, thereby, could be performed only after contrast, thus decreasing overall imaging time. Conversely, the substantial decrease of signal intensity of liver parenchyma can be observed on T2-weighted MR images in 35 minutes. Therefore, we recommend that enhanced T2-weighted MR images should be obtained at the early period after Gd-EOB-DTPA administration between contrast-enhanced dynamic series and hepatobiliary phase imaging.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 62

13:30         4082.     Signal Changes in Liver, Spleen and Bone Marrow at SPIO (Ferucarbotran) Enhanced MR Imaging in Patients with Liver Cirrhosis, Hepatitis and Normal Liver

Akiyuki Torigoe1, Akira Yamamoto1, Takenori Yamashita1, Makito Kobatake1, Shigeru Watanabe1, Daigo Tanimoto1, Akihiko kanki1, Katsuyoshi Ito1

1Kawasaki Medical School, Kurashiki, Okayama, Japan

The purpose of this study was to clarify whether the uptake of SPIO in the spleen increases or decreases at SPIO-enhanced MR imaging in patients with cirrhosis, hepatitis and normal liver, and to evaluate the association with liver and bone marrow uptake of SPIO. Our results showed that the spleen uptake of SPIO increases in cirrhotic patients while the liver uptake of SPIO decreases in cirrhosis. This fact suggested that the spleen and bone marrow uptake of SPIO increase as the other excretion courses when the liver uptake of SPIO decreases in cirrhosis.

14:00         4083.     Dynamic Contrast-Enhanced MRI in Evaluating the Intranodular Hemodynamic Characteristics of Focal Hepatic Nodules in an Experimental Rat Model

Dawei YANG1, Cheng ZHOU2, Zhenghan YANG2, Yue GUO2

1Beijing hospital, Beijing, China; 2Beijing hospital, China

The aim of this study is to investigate the role of Dynamic Contrast-enhanced MRI(DCE-MRI) in the evaluation of the intranodular hemodynamic characteristics of focal hepatic nodules in an experimental hepatocellular carcinoma (HCC) rat model. DCE-MRI was performed in 30 rats with chemically induced hepatocellular nodules ranging pathologically from regenerative nodules (RN) to dysplastic nodules (DN) to HCC, Dynamic enhancement parameters including Time to peak (Tp), maximal relative signal enhancement (REmax), and the initial slope of signal intensity (SI) were measured. Our findings indicates that HCC were markedly hypervascular compared to adjacent cirrhotic liver, while DNs were probably hypo- or isovascular.

14:30         4084.     Characterization of Focal Liver Lesions Using Ferucarbotran-Enhanced Liver MRI: Efficacy of Percentage Signal Intensity Loss for Detecting Nodules Within Diffuse Liver Disease

Chen-Te Chou1,2, Ran-Chou Chen1,3

1Biomedical Imaging and Radiological Science, National Yang-Ming Medical University, Taipei, Taiwan; 2Chang-Hua Christian Hospital, Chang-Hua, Taiwan; 3Radiology, Taipei City Hospital Renai Branch, Taipei, Taiwan

Purpose: To determine the optimal PSIL threshold for characterization of hepatic tumor with diffuse liver disease. Materials and Methods: Fifty patients with diffuse liver disease were included. The PSIL of each lesion was calculated and the diagnostic performance was compared by ROC analysis. Results: The PSILs of the benign lesions were higher than overt HCC, but no significant difference to wHCCs. The optimal PSIL were 35% for FS-T2WI. Sensitivity/specificity for HCC detection were 74.3%/76.2%. Conclusion, with ferucarbotran-enhanced MRI, a PSIL threshold of 35% is useful for the characterization of overt HCC in patients with diffuse liver disease.

15:00         4085.     Assessment of Transporters of Gd-EOB-DTPA in Various Hepatocellular Nodules During Hepatocarcinogenesis Induced in Rat Livers

Natsuko Tsuda1, Osamu Matsui2

1Medical Affairs, Bayer Yakuhin, Ltd., Osaka, Japan; 2Department of Radiology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan

We investigated the difference in the organic anion transporting polypeptide 1 (oatp1) and multidrug resistance protein 2 (mrp2) activity among various differentiated HCC and HPN by laser capture microdissection (LCM) coupled with the reverse transcription polymerase chain reaction (RT-PCR) in order to predict the efficacy of Gd-EOB-DTPA enhanced MRI in the differential diagnosis of these nodules. As a result, the oatp1 activity decreased in the HCC and HPN; however, the mrp2 activity increased in HPN, and decreased in HCC. In addition, it was found that the transporter activity of the borderline legions (high grade HPN and early HCC) showed the similar transporter activity.

 


 
Diffuse Diseases of Liver & Pancreas
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 63

14:00         4086.     Multi-Site Transferability of Image Analysis Methods for Assessing Visceral Adipose Tissue by MRI

Vincenzo Positano1, Francesca Forestieri2, Roberta Petz1, Emma Di Gregorio1, Maria Filomena Santarelli1, Luigi Landini2, Amalia Gastaldelli1

1MRI Laboratory, "G Monasterio" Foundation and Institute of Clinical Physiology, Pisa, Italy; 2Department of Information Engineering, University of Pisa, Pisa, Italy

This study explores the transferability of different image analysis approaches for visceral fat evaluation among images acquired with different scanner and sequences.

14:30         4087.     A Semi-Empirical Predictor for Visceral Fat Fraction from 3D Dual Echo Dixon Technique

Kajoli Banerjee Krishnan1, Uday Patil1, Rakesh Mullick1, Patrice Hervo2

1Imaging Technologies Lab, GE Global Research, Bangalore, Karnataka, India; 2GE Healthcare, Buc, France

We propose a semi-empirical predictor for automatically estimating abdominal visceral fat fraction (VFF) through statistical analysis of VFF computed using a threshold based on acquisition parameters applied to a representative set of MEDAL images in an anatomical region ranging from T12 to lower end of L4 vertebral body. The estimate when applied to three test cases predicts VFF within ±10% of a method in which manually drawn visceral mask on water-only MEDAL image is used to demarcate the subcutaneous layer from the visceral region on the fat-only image. The predictor can be deployed in rapid assessment of obesity-related metabolic health.

15:00         4088.     FSE Triple-Echo Dixon (FTED) Preliminary Experience with a Novel Sequence for Fat Suppressed T2-Weighted Abdominal MR Imaging

Russell Norman Low1,2, Jingfei Ma3, Neeraj Panchal1,2

1Sharp and Children's MRI Center, San Diego, CA, USA; 2San Diego Imaging Medical Group, San Diego, CA, USA; 3University of Texas MD Anderson Cancer Center, Houston, TX, USA

FSE Triple Dixon (FTED) is a prototype sequence producing FSE T2-weighted images with superior fat suppression insensitive to field inhomogeneity. Each FSE readout gradient is replaced with three readout gradient pulses of alternating polarity. The respective echoes occur when fat and water are -180 degrees, 0 degrees, and +180 degrees relative to each other. After acquisition of base images a 2-point Dixon image reconstruction program automatically generates separate water-only and fat-only images for each slice. The efficiency of the FTED sequence allows for breath hold T2-weighted abdominal images without ASSET that demonstrates nearly perfect separation of fat and water signal.

15:30         4089.     Simultaneous R2* and Fat Fraction Determination of the Liver with Modulus and Real Multiple Gradient-Echo MRI

Naoki Ohno1, Tosiaki Miyati1, Eri Ono1, Harumasa Kasai2, Masaki Hara2, Yuta Shibamoto2, Makoto Kawano2, Miyuki Asahi2, Tomoyuki Okuaki3, Tomoyuki Yamamoto4

1Kanazawa University, Kanazawa, Japan; 2Nagoya City University Hospital, Nagoya, Japan; 3Philips Electronics Japan, Tokyo, Japan; 4Kanazawa University Hospital, Kanazawa, Japan

To evaluate the liver metabolism, T2*-IDEAL is useful for assessment when there is co-occurrence of hepatic steatosis and iron deposition, but this method is not necessarily implemented in standard MR imagers. Thus, we devised a method for analyzing R2* (iron content), and fat fraction of the liver tissue simultaneously using modulus and real multiple gradient-echo (MRM-GRE) sequence. The MRM-GRE method makes it possible to simply and accurately assess the fat content and the iron content. The ability to obtain both of them at the same time allows us to optimize the advantages of each and thereby obtain more information about the liver metabolism.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 63

13:30         4090.     MR Elastography for the Early Detection of Steatohepatitis in the Rat with Fatty Liver

Najat Salameh1, Benoît Larrat2, Jorge Abarca-Quinones1, Stéphane Pallu1, Mylène Dorvillius1, Isabelle Leclercq3, Mathias Fink2, Ralph Sinkus2, Bernard E. Van Beers1

1Radiodiagnostic Unit, Université Catholique de Louvain, Brussels, Belgium; 2Laboratoire Ondes et Acoustique, Ecole Supérieure de Physique et Chimie Industrielles, Paris, France; 3Gastroenterology Unit, Université Catholique de Louvain, Brussels, Belgium

The early and non-invasive detection of non-alcoholic steatohepatitis in the fatty liver is difficult. The aim of our study in the rat was to assess the potential value of MR elastography for this non-invasive detection. Our results in the rat suggest that in non-alcoholic fatty liver, MR elastography may be useful for the early detection of steatohepatitis by showing increased elasticity appearing before fibrosis development and linked to myofibroblast activation.

14:00         4091.     Assessment of Hepatic Steatosis, Iron Overload and Combined Disease with 3 Tesla MR Three-Dimensional T1w Two-Point Dixon Imaging: In-Vivo Validation and In-Vitro Calibration of Decomposition Technique

Daniel T. Boll1, Grace M. Redmon2, Stephen I. Zink1, Daniele Marin1, Elmar M. Merkle1

1Radiology, Duke University Medical Center, Durham, NC, USA; 2College Preparatory School for Girls, Hathaway Brown School, Cleveland, OH, USA

Steatosis hepatis functions as an inducer of hepatic iron metabolism dysregulation. 3 Tesla MR two-point Dixon T1w imaging with subsequent comprehensive four-phase decomposition analysis facilitated not only metabolite decomposition of intrahepatic lipids and iron ions in isolated steatosis hepatis and hepatic iron overload, but also allowed decomposition of metabolites in combined disease in a standardized in-vitro liver phantom with in-vivo patient validation.

14:30         4092.     Estimation of Fat Fraction Considering T2* Decay in Liver After SPIO Injection

Tomoyuki Okuaki1,2, Kengo Yoshimitsu3, Ivan Zimine1, Shutaro Saiki1, Marc Van Cauteren4, Toshiaki Miyati5

1Philips Electronics Japan, Minato-ku, Tokoyo, Japan; 2Graduate School of Medical Science, Kanazawa University , Kanazawa, Ishikawa, Japan; 3Radiology,Faculty of Medicine,, Fukuoka University, Fukuoka, Japan; 4Philips Healthcare, Netherlands; 5Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan

Estimation of fat fraction is affected by T2* decay. The aim of this study was to determine the accuracy of fat fraction estimation combined with T2* estimation depending on the number of echoes acquired with a multi-echo gradient echo sequence. 11 volunteers with fatty liver of various degrees were scanned on a 1.5T clinical system. Dual echo T1-weighted fast field echo and multi-echo fast field gradient echo, before and after SPIO administration. Fat fraction maps from dual echo data and mFFE data were compared before SPIO injection and for each acquired time point after injection. For each time point fat fraction ratio (FFr) maps were calculated as post-contrast data divided by pre-contrast data and average values across time points from manually placed ROIs was used for comparison. FFr by dual echo method was 0.32}0.28, by mFFE method using 3 echoes (1.03 } 0.11), 4echoes (1.00 } 0.07), 6 echoes (1.04 } 0.05), 8 echoes (1.12 } 0.08) and 10echoes (1.32 } 0.05). With Dual echo method, fat fraction is clearly underestimated because of unaccounted T2* decay, while with mFFE, the ratio stays close to expected 1.0. Accurate estimation of fat fraction accounting T2* decay is possible using mFFE method in the liver, even in patients with iron accumulation. Considering that abdominal imaging requires breath holding, and that the results for 3, 4, 6, and 8 echoes are not significantly different, the use of smallest number of echoes is justified.

15:00         4093.     Single Breath Hold Multi-Echo Liver Fat Quantitation

Marko K. Ivancevic1,2, Jouke Smink3, Hero K. Hussain2, Thomas L. Chenevert2

1MRI, Philips Medical Systems, Cleveland, OH, USA; 2Radiology, University of Michigan, Ann Arbor, MI, USA; 3MRI, Philips Medical Systems, Best, Netherlands

Magnetic resonance imaging and spectroscopy provide a tool for fat quantitation for a wide range of liver conditions such as steatosis, non alcoholic fatty liver disease (NAFL), or non alcoholic steatohepatitis (NASH). Various methods are being used for fat quantitation, such as MR spectroscopy or 3-point Dixon. A practical method based on dual flip angle, in-phase and out-of-phase echoes and T2* correction has been developed. Here we present an improvement of the method, where we acquired 6 echoes (3 in-phase/out-of-phase pairs) with 2 flip angles providing fat quantitation and T2* correction in a single breath hold scan.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 63

13:30         4094.     Quantification of Iron Deposition in Chronic Liver Disease

Andrew Dean Hardie1

1Radiology, Medical University of South Carolina, Charleston, SC, USA

Utilizing a multi-echo gradient echo sequence, hepatic iron deposition was assessed quantitatively in patients with chronic liver disease and in controls. There was significantly greater liver iron deposition among those with chronic liver disease than those without, as indicated by a lower mean T2* value of the liver parenchyma. This was true even when patients with potential hemochromatosis were excluded. Given that iron deposition may be both an indicator of the severity of ongoing chronic liver disease and may be a risk factor for the development of hepatoma, this method has potential utility in identifying both the presence and severity of iron deposition in individual patients.

14:00         4095.     Evaluation of the Liver Iron Concentration (LIC) at 3T in Comparison to 1.5T in Patients with Thalassemia and Falciforme Anemia

Thomas Martin Doring1,2, Flavia P. Junqueira3, G M. Cunha3, Antonio C. Coutinho Jr. 3, Antonio Adilton Carneiro4, Marcio Bernardes3, J L. Fernandes5, Romeu Cortes Domingues3

1Radiology, Multi-imagem, Rio de Janeiro, RJ, Brazil; 2Radiology, UFRJ - Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; 3Radiology, CDPI, Rio de Janeiro, RJ, Brazil; 4Medical Physics, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil; 5UNICAMP, Campinas, Brazil

Relaxometry (T2*) was performed at 3T and compared to 1.5T in establishing a relationship between the results. The liver iron concentration (LIC) at 1.5T was calculated through calibration of the MR scanner and at 3T a correction factor, extracted from the T2* relationship between the different field strengths, was applied with the goal to use the same calibration equation of the 1.5T scanner. The T2* measurements and liver iron concentrations, with the application of the correction factor, at 3T and 1.5T showed high linear relationship.

14:30         4096.     SPIO-Enhanced MR Evaluation of Regional Hepatic Blood Flow

Takeshi Yoshikawa1, Shohei Miyazaki2, Nobukazu Aoyama3, Kenya Murase2, Yoshiharu Ohno1, Tetsuo Maeda1, Hideaki Kawamitsu3, Kazuro Sugimura1

1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Medical Physics and Engineering, Osaka University Graduate School of Medicine Faculty of Health Science, Suita, Osaka, Japan; 3Central Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan

Regional hepatic blood flow can be estimated by SPIO-enhanced dynamic MR imaging and two-input, one-compartment model. The estimated values have the potential to be used for evaluation of regional hepatic function.

15:00         4097.     Getting More Out of 31P MRS of the Human Liver Moving from 1.5T to 3T

Ronald Ouwerkerk1, Alena Horska1,2, Michael Schär3, Susanne Bonekamp1, Mariana Lazo4, Jeanne M. Clark4,5

1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; 2Neuroradiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; 3Philips Healthcare, Cleveland, OH, USA; 4Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; 5Medicine, General Internal Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA

An upgrade from 1.5T to 3T is expected to improve 31P liver MRS, but causes continuity problems in a longitudinal study. ISIS-localized and 1H-decoupled 31P MR spectra, recorded with nearly identical acquisition parameters and localized volumes at 1.5T and 3T were analyzed for changes in quality and quantitation of metabolites. Relative signals of β-ATP and PME were the same for both fields, but different for other metabolites. Higher field yielded a marked improvement in potential to detect low level di-phosphate metabolites, individual phospho-monoesther (PME) and -phospho-diester peaks and enabled accurate measurement of intracellular pH from the inorganic phosphate shifts.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 63

13:30         4098.     Differential Profile of Body Fluid Change in Type II Diabetic Patients and Healthy Volunteer Subjects Following Pioglitazone Treatment

Young-Hoon Sung1, Chun S. Zuo2, Annaswamy Raji3, Robert L. Dobbins4, Derek J. Nunez4, Donald C. Simonson3, Rosemond A. Villafuerte2, Rebecca J. Hodge4, Sam R. Miller5, Andrew P. Brown4, Perry F. Renshaw1, Michael E. Henry2

1University of Utah, Salt Lake City, UT, USA; 2McLean Hospital, Belmont, MA, USA; 3Brigham and Women's Hospital, Boston, MA, USA; 4GlaxoSmithKline, RTP, NC, USA; 5GlaxoSmithKline, Harlow, UK

Pioglitazone is associated with clinically significant edema. However, relatively little information is available to exactly quantify the amount of body fluid accumulated. In the present study, we have utilized both proton and sodium MRI to evaluate the occurrence of edema during eight weeks of pioglitazone treatment in twelve Type II diabetes mellitus patients and six healthy subjects. For parallel evaluation and comparison of edema index, conventional measurements including tracer methods, hematologic assays, blood chemistry, body weight, pitting edema, were also assessed. Our MRI results suggest that proton T2 measurement offer more sensitive detection of edema than proton T1 or sodium MRI and are well consistent with the clinical and other laboratory data. The present study also indicates diabetes patients and healty subjects respond differently to pioglitazone treatment in terms of fluid retention.

14:00         4099.     Pilot Investigation of Intramyocellular and Abdominal Lipid Contents by 2D MR Spectroscopy and MRI in Patients with Type2 Diabetes and Impaired Fasting Glucose

Aparna Singhal1, Preethi Srikanthan2, Neil Wilson1, Anthony Sosa2, Sendhil Velan3, Nagesh Ragavendra1, RK S. Rathore4, Rakesh K. Gupta5, Michael Albert Thomas1

1Radiology, UCLA, Los Angeles, CA, USA; 2Endocrinology, UCLA, Los Angeles, CA, USA; 3Radiology, West Virginia University, Morgantown, WV, USA; 4IIT, Kanpur, UP, India; 5Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, UP, India

Calf muscle was investigated in 10 subjects with impaired fasting glucose or early diabetes using single-voxel-based 2D L-COSY. Correlation of MRS ratios was evaluated with carotid intimal thickness measured by ultrasonography, abdominal fat calculated using T1-weighted MRI and blood tests including hs-CRP as marker of inflammation. Various significant correlations were seen between muscle lipids and other parameters but hs-CRP did not show any significant correlations. In early stages of diabetes, intramyocellular fat deposition is closely related to the extent of atherosclerosis and insulin resistance and intracellular fat deposition is more strongly associated with insulin resistance and atherosclerosis than extracellular deposits.

14:30         4100.     Hepatic Phosphorus Metabolite Concentrations of Patients with Type 2 Diabetes Assessed by 31P 3D MRSI

Marek Chmelik1,2, Albrecht Ingo Schmid1, Stephan Gruber1,3, Wolfgang Bogner1,3, Julia Szendroedi4, Martin Krssak1,3, Siegfried Trattnig1,3, Ewald Moser1,5, Michael Roden4,6

1MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 2Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria; 3Department of Radiology, Medical University of Vienna, Vienna, Austria; 4Institute for Clinical Diabetology, German Diabetes Center, Dusseldorf, Germany; 5Center for Biomedical Engineering and Physics, Medical University of Vienna, Vienna, Austria; 6Department of Medicine/Metabolic Diseases, Heinrich Heine University , Dusseldorf, Germany

Non-alcoholic fatty liver in insulin-resistant and/or type 2 diabetic patients (T2DM) can be underlain by abnormalities in energy metabolism. The purpose of this study was to apply recently developed protocol and asses in vivo hepatic phosphorus metabolite concentrations of patients with T2DM and their age and BMI-matched controls (mCON). T2DM had 23% and 20% lower Pi and g-ATP than mCON, whereas mCON had comparable concentrations than recently published young healthy volunteers. The reduction of energy metabolites could be explained by abnormalities in hepatic mitochondrial function and insulin resistance of T2DM patients.

15:00         4101.     Estimation of Liver Fat Fraction Using MR Spectroscopy and Multi-Echo MRI : Clinical Evaluation in Diabetic Population

Ramkumar Krishnamurthy1, Medhavi Jogi2, Debra Dees3, Raja Muthupillai3, Mandeep Bajaj2

1Department of Bioengineering, Rice University, Houston, TX, USA; 2Baylor-SLEH Diabetes program, Baylor College of Medicine, Houston, TX, USA; 3Department of Radiology, St.Luke’s Episcopal Hospital and Texas Heart Institute, Houston, TX, USA

Liver fat-fraction is estimated at the right-anterior, right-posterior and left lobes using MR spectroscopy and imaging (multiple echo method). Accurate fat quantification was performed by obtaining dual echo (in-phase and out-phase) images at flip angles of 20 and 70 degrees. Good correlation was observed between the spectroscopic and imaging data. Inter-regional variation of fat within liver was minimal.

 


 
Renal Functional
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 64

14:00         4102.     Nephrogenic Systemic Fibrosis in Liver Disease:  a Systematic Review

Sameer M. Mazhar1, Masoud Shiehmorteza2, Michael S. Middleton2, Claude B. Sirlin2

1Department of Medicine, Division of Gastroenterology, University of California, San Diego, San Diego, CA, USA; 2Department of Radiology, University of California, San Diego, San Diego, CA, USA

Gadolinium-based contrast agents have been implicated in the pathogenesis of nephrogenic systemic fibrosis. The FDA has released a black box warning cautioning against the use of gadolinium in patients with liver disease. Our review of the literature, however, does not suggest that liver disease confers an increased risk for NSF beyond that of the underlying renal insufficiency.

14:30         4103.     Characterization of Renal Masses: Is There a Threshold for Differentiating Noise from True Enhancement on Subtraction Imaging?

Samson Wong1, Sooah Kim1, Nicole Hindman1, Daniel Sahlein1, Vivian S. Lee1

1Radiology, New York University, New York, NY, USA

Postprocessing image subtraction has been used successfully in MR in characterizing and evaluating enhancement of renal lesions. Image noise, however, is a potential pitfall in MR subtraction imaging. Our objective was to evaluate if there is a threshold signal-to-noise ratio of subtraction images for distinguishing nonenhancing from enhancing renal lesions. We evaluated the approximate SNR (aSNR) of MR subtracted images of nonenhancing lesions (simple cysts and T1 hyperintense cysts) and renal neoplasms and found that the aSNR of cysts were significantly lower than renal neoplasms (p<.001). In addition, a cutoff aSNR value of 10 achieved a 100% specificity and sensitivity.

15:00         4104.     Imaging of Different Subtypes of Solid Renal Tumors

Ewtim Rainer Dabew1, Peter Fries1, Marcus Katoh1, Frank Becker2, Arno Bücker1, Günther Schneider1

1Clinic of Diagnostic and Interventional Radiology, University Hospital of Saarland, Homburg, Germany; 2Clinic of Urology and Paediatric Urology, University Hospital of Saarland, Homburg

In renal cell carcinoma a differentiation of the histological subtype cannot be stated neither on unenhanced nor on contrast enhanced MR images. MR perfusion studies were performed in a total of 34 patients with renal masses before surgery acquiring a turbo-flash sequence to evaluate whether the perfusion kinetics in contrast-enhanced MRI might allow for further characterization of solid renal masses. The perfusion kinetics of various solid renal masses however did not show significant differences in contrast-enhanced MRI and therefore as well can not be used for further subcategorization of malignant renal tumors.

15:30         4105.     Diffusion Weighted MRI in Assessment of Renal Masses

Kumaresan Sandrasegaran1, Fatih M. Akisik1, Chandru P. Sundaram2, Magnus P. Rydberg1, Chen Lin1, Alex M. Aisen1

1Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; 2Surgery, Indiana University School of Medicine, Indianapolis, IN, USA

ADC measurements obtained with DWI at 1.5 T may aid in the differentiation on renal masses, particularly benign from malignant cystic lesions.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 64

13:30         4106.     Acute Ureteral Obstruction: Monitoring Treatment by  Blood Oxygenation Level-Dependent MRI

Peter Vermathen1, Sonia C. Simon-Zoula2, Tobias Binser1, Thomas M. Kessler3, Maria Triantafyllou2, Chris Boesch1, Urs E. Studer3, Harriet C. Thoeny2

1Dept. Clinical Research / AMSM, University Bern, Bern, Switzerland; 2Department of Radiology, University & Inselspital, Bern, Switzerland; 3Department of Urology, University & Inselspital, Bern, Switzerland

BOLD-MRI yields the relaxation rate R2*, which is considered to be inversely related to tissue pO2. This study aimed at determination whether response to treatment in ureteral obstruction can be monitored by BOLD-MRI.

14:00         4107.     Evaluation of the Feasibility and Reproducibility of BOLD MRI in Healthy Volunteers Compared to Kidney Transplant Patients – Preliminary Study

Marica Cutajar1, Stephen D. Marks2, Paul Brogan3, Isky Gordon1

1Radiology and Physics, UCL Institute of Child Health, London, UK; 2Renal Unit, Great Ormond Street Hospital, London, UK; 3Dept of Rheumatology, UCL Institute of Child Health, London, UK

In the past few years a lot of work has gone into investigating the application of BOLD MRI in diagnosing renal abnormalities. In this study, T2* weighted BOLD MR images were acquired performed using a multi-gradient-recalled-echo sequence with 12 echoes. This study was performed firstly to assess the oxygenation state of healthy native and transplant kidneys and, secondly, to evaluate the feasibility and reproducibility of BOLD MRI in healthy volunteers and compare this to kidney transplant patients. All volunteers were asked to hold their breath during the scans to avoid movement errors in the images. R2* values were calculated which reflect the deoxyhaemoglobin levels present in the kidney.

14:30         4108.     Development of a Method for Measuring the Dynamics of Oxygen Consumption in the Kidney Using Blood Oxygenation Level-Dependent Magnetic Resonance Imaging

Yoshinori Kusakabe1, Yasuyoshi Inoue1, Koji Okada1, Youichi Yamazaki1, Kenya Murase1

1Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan

The purpose of this study is to develop a method for measuring the dynamics of oxygen consumption in the kidney using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). The BOLD MRI studies were performed in anesthetized Sprague-Dawley rats. To investigate the effects of diuretics on the oxygen consumption in the kidney, we administered saline, furosemide, acetazoramide, or mannitol as diuretics. When furosemide was administered, there was a significant change in oxygen consumption in the medulla compared to that in the control group. Our method appears to be useful for measuring the dynamics of oxygen consumption in the kidney.

15:00         4109.     Evaluation of Intra-Renal Oxygenation in Db/db Mice by BOLD MRI

Lu-Ping Li1, Sarah Halter1, JoAnn Cabray1, Pottumarthi V. Prasad1

1Radiology, Northshore University Healthsystem, Evanston, IL, USA

Mouse models provide an excellent opportunity to study mammalian diseases such as diabetic nephropathy where a role for genetics is suspected. Renal hypoxia is a critical pathway leading to end stage renal failure. The objective of this work was to extend previous observations using BOLD MRI in type I diabetes model in rats to an inbred mouse model of type II diabetes. Intra-renal BOLD MRI measurements showed lower renal medullary and cortical oxygenation levels in Type II diabetic mice (db/db) compared to their healthy littermates (db/m). The level of hypoxia was higher at 15 compared to 10 weeks of age.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 64

13:30         4110.     Variability of Renal ADC: Limitations of Monoexponential Model

Jeff Lei Zhang1, Eric E. Sigmund1, Henry Rusinek1, Hersh Chandarana1, Qun Chen1, Pippa Storey1, Louisa Bokacheva1, Vivian S. Lee1

1Radiology, New York University, New York, NY, USA

Previously reported values of ADC in healthy kidneys vary considerably. In this study, high quality volunteer data were acquired and were fitted by mono-exponential model. Fitting the data at 19 sets of b values used in literature resulted in predicted ADC values from 2.1x10-3 to 3.1×10-3 mm2/s. Significant correlation was found between the predicted and the reported values for cortex (R2 = 0.50) and medulla (R2 = 0.28). This indicates that the substantial variability among reported values in the literature is due to the application of monoexponential model to renal diffusion data that reflect substantial vascular and tubular flow effects.

14:00         4111.     Quantification of Renal Diffusion-Weighted Images Using a Bi-Exponential Model

Jeff Lei Zhang1, Eric E. Sigmund1, Henry Rusinek1, Hersh Chandarana1, Qun Chen1, Pippa Storey1, Louisa Bokacheva1, Vivian S. Lee1

1Radiology, New York University, New York, NY, USA

In diffusion weighted imaging of kidney, “intravoxel incoherent motion (IVIM)” has been shown to contribute substantially to overall signal decay. We hypothesize that IVIM in kidney reflects both renal perfusion and tubular fluid flow. A bi-exponential model was used to analyze volunteer data. Minimal difference was found for pure diffusion coefficient (ADCD) between cortex and medulla, suggesting that the commonly observed ADC contrast between cortex and medulla is in fact due to IVIM effect. Perfusion faction FP was estimated as 31%~38%, much higher than 5%~15% observed in perfusion imaging, indicating that the IVIM effect likely contains a significant tubular contribution.

14:30         4112.     Evaluation of Normal and Dysfunctional Renal Transplants Using DTI

Hersh Chandarana1, Vivian S. Lee1, David Stoffel1, Laura Barisoni-Thomas2, Devon G. John3, Thomas Diflo3, Eric E. Sigmund1

1Radiology, NYU Langone Medical Center, New York, NY, USA; 2Pathology, NYU Langone Medical Center, New York, NY, USA; 3Transplant Surgery, NYU Langone Medical Center, New York, NY, USA

Renal tubular structure and function may be investigated non-invasively using diffusion tensor imaging (DTI). Patients with healthy and diseased renal allografts were investigated with DTI. Our study demonstrates higher medullary fractional anisotropy (FA) in normal transplant compared to patient with acute rejection, which has little corticomedullary differentiation. Inflammatory changes in the renal medulla due to acute rejection with disruption of tubular structure and function is entertained as a possible hypothesis. This study suggests possible role for DTI in evaluation of renal dysfunction.

15:00         4113.     Evaluation of Renal Allograft Function Early After Transplantation with Diffusion-Weighted MR Imaging - Initial Experience

Ute Eisenberger1, Tobias Binser2, Chris Boesch2, Felix J. Frey1, Peter Vermathen2, Harriet C. Thoeny3

1Department of Nephrology, University & Inselspital, Bern, Switzerland; 2Dept. Clinical Research / AMSM, University Bern, Bern, Switzerland; 3Department of Radiology, University & Inselspital, Bern, Switzerland

Diffusion-weighted MRI (DWI) was performed in 15 renal allograft recipients early after transplantation. Diffusion parameters were determined, including calculation of ADCs and micro-perfusion (FP) contributions. Ten patients hat good allograft function, four patients presented with histologically proven acute rejection (AR), and one patient with acute tubular necrosis (ATN).

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 64

13:30         4114.     Assessing Native and Transplant Kidneys with Diffusion Weighted MR Imaging:  Mean Vs Delta ADC

Robert W. Garrett1, Karl Vigen1, Sean Fain2, Garima Agrawal1, Thomas Grist1, Elizabeth A. Sadowski1

1Department of Radiology, University of Wisconsin, Madison, WI, USA; 2Department of Medical Physics, University of Wisconsin, Madison, WI, USA

The purpose of our study was to evaluate the mean cortical and medullary ADC values in both native and transplant kidneys with normal function versus diminished function, and determine the utility of using the corticomedullary ADC difference (delta ADC) to differentiate between these groups. A decrease in delta ADC was noted between the normal and diminished functioning natives and the normal and diminished functioning transplants, however statistical significance was present only in the native kidney group. The delta ADC value is a novel technique which, along with mean medullary and cortical ADC values, may differentiate kidneys based on function.

14:00         4115.     DTI of Human Kidney at 3T - Simultaneous and Reliable Determination of Fractional Anisotropy, ADC and Perfusion Fraction

Tobias Binser1, Harriet C. Thoeny2, Chris Boesch1, Peter Vermathen1

1Dept. of Clinical Research, University of Bern, Bern, Switzerland; 2Dept. of Radiology, Inselspital Bern, Bern, Switzerland

Aim of this study was to evaluate the potential of diffusion tensor imaging (DTI) to reliably determine the fractional anisotropy (FA), apparent diffusion coefficient (ADC) and perfusion fraction (FP) in human kidney at 3T. Therefore 13 volunteers were investigated with single-shot echo-planar imaging applying ten different b-values in 6 non-collinear directions. The diffusion parameters exhibit only little standard deviations and agree with literature. ADC and FP match well with results obtained by diffusion-weighted imaging (DWI). The findings suggest that DTI is capable to provide direction-dependent information like FA in addition to ADC and FP without major drawbacks compared to DWI.

14:30         4116.     Diffusion-Weighted MR Imaging (DWI) in Adrenal Lesions: Clinical Applications

Yi Wang1, Robert J. Mccarthy2, Laura Merrick3, Paul Nikolaidis3, Vahid Yaghmai3, Riad Salem3, Frank H. Miller3

1Radiology , Northwestern University , Chicago , IL, USA; 2Anesthesia, Northwestern University, USA; 3Radiology, Northwestern University, Chicago, IL, USA

Diffusion-weighted MR has recently been used in body imaging for distinguishing benign from malignant lesions; however, imaging findings in the adrenal have not been well described. We reviewed our experience to determine if there was a correlation between ADCs and adrenal lesions. 158 lesions were evaluated by DWI, including 118 adenomas, 9 myelolipomas, 9 cysts, 9 metastases, 4 adrenal cortical carcinomas, 4 hemorrhage, 3 pheochromocytomas, 1 angiolipoma, and 1 neuroblastoma. The mean ADC value of benign lesions was 1.69±0.59 and malignant was 1.86±0.92 (p>0.05) with no statistical difference (p>0.05). Diffusion-weighted MR could not characterize benign and malignant lesions due to significant overlap.

15:00         4117.     Evaluation of 3.0T MR Diffusion-Weighted Imaging in Renal Malignant Tumor

Yu Xiaoduo1, Ou Yanghan1

1Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China

DWI in 3.0T MRI made it possible to diagnose tumor, which can be quantitatively measured by ADC value. Comparison of ADC value was performed in 66 renal malignant tumors. Significant differences were found between normal renal cortex and renal carcinoma, non-clear cell carcinoma and clear cell carcinoma respectively. Among groups of clear cell carcinoma, there were statistic differences between grade¢ñ and ¢ó, grade ¢òand ¢ó respectively. Therefore 3.0T MR-DWI can be used in diagnosis of renal malignant tumor, while ADC value was helpful in differentiating its pathological type and grade.

 


 
Breast MR: Density, Diffusion
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 65

14:00         4118.     Diffusion MR Imaging: ADC Mapping of Malignant and Benign Breast Tumors

Sunitha B. Thakur1,2, Nicole Ishill3, David D. Dershaw4, Jason A. Koutcher1,4, Elizabeth A. Morris4

1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 2Radiology,  Memorial Sloan Kettering Cancer Center, New York, NY, USA; 3Epidemiology-Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 4Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA

We presented the first phase of an ongoing investigation aimed at establishing the clinical usefulness of diffusion weighted imaging and apparent diffusion coefficients (ADCs) for breast cancer diagnosis. ADC values of confirmed malignant lesions were much lower than those of benign lesions. Since ADC values are roughly proportional to cellular density, they represent a valuable biomarker for detecting malignant lesions. Histopathology was used as the reference standard. Although this study was conducted on a limited population, the findings suggest that the measurement of extracellular water content may be an additional feature that can improve MRI specificity and understand treatment changes.

14:30         4119.     Diffusion Weighted Imaging of the Breast at 3.0T with BLADE-TSE: Initial Experience

Chen Lin1, Christian Geppert2, Alto Stemmer2, helmuth Schultze-Haakh2, Shadie S. Majidi1, Hal Douglas Kipfer1

1Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; 2Siemens Healthcare

BLADE-TSE which is less susceptible to artifacts due to field inhomogeneity than single-shot EPI is shown to provide superior image quality for diffusion weighted imaging of the breast at 3.0T.

15:00         4120.     Diffusion Imaging of the Breast - Pearls and Pitfalls Learned During Routine Clinical Use

Frederick Kelcz1

1University of Wisconsin, Madison, Madison, WI, USA

We added Diffusion Weighted Imaging to routine Breast MRI two years ago. We have learned that DWI offers an exciting contrast mechanism offering information orthogonal to that derived from contrast enhancement. In this image intensive teaching poster we share our experience and offer suggestions helpful in using DWI to improve MRI specificity.

15:30         4121.     Validation of a Nonrigid Registration Algorithm for Longitudinal Breast MR Images

Xia Li1, Benoit Dawant2, E. Brian Welch1,3, A. Bapsi Chakravarthy4, Darla Freehardt4, Ingrid Mayer5, Mark Kelley6, Ingrid Meszoely6, John Gore1, Thomas Yankeelov1

1Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; 2Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, USA; 3Philips Healthcare; 4Radiation Oncology, Vanderbilt University, Nashville, TN, USA; 5Medical Oncology, Vanderbilt University, Nashville, TN, USA; 6Surgical Oncology, Vanderbilt University, Nashville, TN, USA

The analysis of dynamic contrast enhanced MRI provides relevant information on tumor status. We have proposed a method whereby the longitudinal breast DCE-MRI data sets are co-registered, thereby retaining spatial information so that DCE-MRI parameter maps can be compared on a voxel-by-voxel basis. We accomplished this by extending the adaptive bases algorithm through adding a tumor-volume preserving constraint in the cost function. The visual assessment shows the proposed algorithm can successfully register the breast MR images. In this study, a novel validation method is proposed here to simulate the deformation of the longitudinal breast MR images and verify different nonrigid registration algorithms accurately.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 65

13:30         4122.     Ductal Carcinoma in Situ Diagnosed with Contrast-Enhanced Breast MR Imaging. Can Invasion Be Predicted?ξ

Mariko Goto1, Sachiko Yuen1, Kei Yamada1, Eiichi Konishi2, Tsunehiko Nishimura1

1Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan; 2Pathology, Kyoto Prefectural University of Medicine

Aim of this study is to retrospectively evaluate whether magnetic resonance (MR) imaging features can be used to predict which cases diagnosed as ductal carcinoma in situ (DCIS) without invasion by means of needle biopsy will have invasive disease at surgery. In this study, we found the MR imaging features were useful for the diagnosis of occult invasion in DCIS, especially ¡Ý 1cm histological invasive nest within the DCIS. That is considered for helpful to decide appropriate location of needle biopsy.

14:00         4123.     Clinicopathological Correlation of Residual Breast Cancer Diagnosed by MRI in Patients Receiving Neoadjuvant Chemotherapy with and Without Bevacizumab (Avastin®)

Shadfar Bahri1, Jeon-Hor Chen1,2, Ke Nie1, Rita S. Mehta3, Philip M. Carpenter4, Soon-Young Kwon4, Hon J. Yu1, Orhan Nalcioglu1, Min- Ying Su1

1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Department of Radiology, China Medical University Hospital, Taichung, Taiwan; 3Department of Medicine, University of California, Irvine, USA; 4Department of Pathology, University of California, Irvine, USA

The pathological response in breast cancer patients receiving anti-angiogenic therapy using Avastin, and the impact of Avastin on diagnostic performance of MRI after therapy was investigated. The pCR rates and residual disease patterns were comparable between patients receiving Avastin vs. those not. The size measured on MRI was highly accurate for mass lesions that shrank down to nodules. For residual disease as scattered cells within a large fibrotic region, MRI could not predict them accurately. The fact that the accuracy of MRI was comparable between 2 groups suggests that treatment with Avastin did not compromise the diagnostic accuracy of MRI.

14:30         4124.     Characterization of Breast Tumors with Functional Imaging: Evaluation with Real-Time Ultrasound Elastography and Diffusion-Weighted MR Imaging with Apparent Diffusion Coefficient (ADC) Value Analysis

Naoto Egashira1, Katsuyoshi Ito1, Takenori Yamashita1, Teruki Sone1, Tsutomu Tamada1, Akira Yamamoto1

1Dept. of  Radiology, Kawasaki Medical School, Kurashiki, Okayama, Japan

Real-time ultrasound elastography and diffusion-weighted MR imaging with ADC value analysis are useful, functional imaging techniques in the characterization of benign and malignant breast tumors.

15:00         4125.     MRI Quantitative Changes of Breast Tissue Composition with Short-Term Tamoxifen Treatment in Cancer Patients.

Abimbola Oluwayemisi Orisamolu1, Catherine S. Klifa1, Sachiko Anne Suzuki1, Juan Nicolas Lessing2, Jessica E. Gibbs1, Dorota Jakubowski-Wisner1, Bonnie N. Joe1, Eunsil Shelley Hwang2, Nola M. Hylton1

1Radiology, University of California, San Francisco, San Francisco, CA, USA; 2Surgery, University of California, San Francisco, San Francisco, CA, USA

In this project we quantified changes in breast tissue composition following 3 months of tamoxifen therapy in 16 premenopausal patients with Ductal Carcinoma in Situ (DCIS). Contrast-enhanced MRI data were obtained before and after tamoxifen treatment, before surgery. Volumetric breast density was extracted from MRI data at all time points, and defined as the ratio of fibroglandular tissue volume over total breast volume. Results show a mean MR breast density decrease of 13.5% during the 3 months therapy, in women with mixed MR density. These results suggest that tamoxifen affects breast density even in a short duration therapy and that these effects are quantifiable using MRI.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 65

13:30         4126.     Quantitative Measures of Breast Density and Tissue Patterns Using MRI

Catherine Klifa1, Julio Carballido-Gamio1, Jessica Gibbs1, Nola Hylton1

1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA

We investigated quantitative measures of breast MRI tissue patterns. High breast density is a strong marker for breast cancer risk and mammography is currently the approved modality for breast density assessment but performs poorly in women with dense breasts. MRI provides very good soft-tissue contrast and 3D information on breast tissue content. We showed that women with similar mammographic densities may present very different tissue patterns on MRI. We defined new quantitative measures using breast MRI data of 50 normal volunteers and showed that a new MR breast tissue index may provide complementary information to MR breast density. Our new MRI quantitative measures could have applicability to improve breast cancer risk assessment techniques.

14:00         4127.     Mammographic and MR Density  in Dense Breasts: Is There a Correlation?

Priya Kumar Sareen1, Ava Kwong2,3, Debra M. Ikeda4, Catherine Klifa5

1Breast Imaging, Stanford University, Stanford, CA, USA; 2Consulting Assistant Professor, Department of Breast Surgery, Stanford University, Stanford, CA, USA; 3Chief of Breast Surgery Division, University of Hong Kong Medical Centre, Hong Kong; 4Radiology, Stanford University, Stanford, CA, USA; 5Radiology, UCSF, San Francisco, CA, USA

There is a well-described correlation between mammographic density and breast cancer risk. Chinese women in Hong Kong (HK) have been shown to have dense breasts. MRI used as tool to measure breast density eliminates the radiation dose and uses 3D information. We utilized a semiautomatic 3D fuzzy C-means segmentation technique to quantify breast tissue and total breast volume from the patients’ MRIs, to determine MR breast density, and compared it to mammogram density and pattern. 2D mammography predicted breast densities at least twice greater than that measured by the MR quantitative method. MRI may be more accurate than mammography in calculating the percent of actual fibroglandular tissue relative to the total breast volume in women with dense breasts.

14:30         4128.     MR-Based Computer-Aided Breast Density Measurement Compared with Mammographic Measurement

Byron A. Feig1, Jeon-Hor Chen1,2, Ke Nie1, Thomas J. Bakondy3, Vashita Dhir3, Kenneth Meng3, R Oganeseyan3, Orhan Nalcioglu1, Min-Ying Lydia Su1

1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Department of Radiology, China Medical University, Taichung, Taiwan; 3Department of Radiology, University of California Irvine Medical Center, Orange, CA, USA

Breast density measured by computer-algorithm based quantitative analysis on MRI, and the density evaluated on mammogram by radiologists based on BI-RADS category and the deciles percent density were compared. The Pearson correlation only yielded a loose positive correlation. The subjective assessment of breast density by radiologists was highly variable. The results suggested that mammographic density is highly susceptible to reader variation and the intrinsic limitation due to the nature of the projection on mammogram. A small amount of scattered dense tissues within the breast could yield a moderate density on the projection mammogram. The clinical significance of the MRI-based density analysis warrants further investigation.

15:00         4129.     Exclusion of Skin for Measurement of Fibroglandular Breast Density on 3D MRI

Ke Nie1, Daniel Chang1, Jeon-Hor Chen1,2, Chieh-Chih Hsu2, Tzu-Ching Shih1,3, Hoanglong Nguyen1, Muqing Lin1, Orhan Nalcioglu1, Min-Ying Lydia Su1

1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, USA; 2Department of Radiology, China Medical University, Taichung, Taiwan; 3Department of Medical Radiology Technology, China Medical University, Taiwan

This study investigated the effect of skin contamination in the breast density measurement by MRI. Skin has isointense signal as the fibroglandular tissue, and if not properly excluded would result in a large error. Using 50 cases with different breast sizes, we measured the volume of the skin and the breast, and built models to provide an estimate of skin volume based on breast volume. When MRI-based method will be applied to measure small change of density over time, reliability is the key to success, and the effect of skin needs to be properly handled.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 65

13:30         4130.     Clinical Assessment of Complex Valued Combinations of Ip- And Op-Data in MR Mammography

Karl-Heinz Herrmann1, Pascal AT Baltzer, Alexander Rauscher2, Hartmut P. Burmeister, Werner A. Kaiser, Jürgen R. Reichenbach1

1Medical Physics Group, Institute for diagnostic and  interventional  radiology, Jena, Thuringia, Germany; 2UBC MRI Research Centre, Vancouver, BC

The complex valued combination of in-phase and opposed-phase data can improve image quality and lesion contrast in dynamic MR mammography (MRM). In diagnostic reading of MRM, descriptors like border sharpness are important morphological criteria for lesion classification. In this clinical evaluation, two independent radiologists rated four contrasts (conventional ip-subtraction, magnitude ip-op-subtraction, complex ip-op-addition and a maximum intensity projection (MIP) of these complex contrasts) regarding image quality and lesion border delineation. Both observers rated the complex MIP contrast as clearly superior to all other contrasts.

14:00         4131.     Increasing the Scanning Efficiency of 3D FSE – IDEAL for Volumetric Breast Coverage

Ananth J. Madhuranthakam1, Ann Shimakawa2, Huanzhou Yu2, Martin P. Smith3, Reed F. Busse4, Scott B. Reeder5, Neil M. Rofsky3, Jean H. Brittain4, Charles A. McKenzie6

1Applied Science Laboratory, GE Healthcare, Boston, MA, USA; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA, USA; 3Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA; 4Applied Science Laboratory, GE Healthcare, Madison, WI, USA; 5Radiology, Medical Physics, Biomedical Engineering and Medicine, University of Wisconsin, Madison, WI, USA; 6Medical Biophysics, University of Western Ontario, London, ON, Canada

Water-fat separation with T2-weighted 3D-FSE-IDEAL requires three separate images at different echo times with respect to the spin echo. Rather than acquiring each of these echoes in separate TRs, we developed a technique to acquire two gradient echoes per refocusing pulse in each TR. Further, to acquire the optimal echo shifts that maximize SNR performance we used fractional readout acquisition. Utilizing all the four gradient echoes with a combined IDEAL homodyne reconstruction, we are able to obtain high quality water-fat separated 3D images of both breasts with near-isotropic ~1.5 mm resolution in approximately 7 minutes.

14:30         4132.     MR Mammography at 7 Tesla: Preliminary Results

Lale Umutlu1,2, Stefan Maderwald1,2, Oliver Kraff1,2, Jens M. Theysohn1,2, Sherko Kuemmel3, Elke A. Hauth1,2, Michael Forsting1,2, Gerald Antoch1,2, Mark E. Ladd1,2, Harald H. Quick1,2, Thomas C. Lauenstein1,2

1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany; 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, NRW, Germany; 33Department of Gynecology and Obstetrics, University Hospital Essen, Essen, NRW, Germany

Within the last three decades, breast MR imaging has emerged from low to high magnetic field strength by overcoming RF-related limitations of SAR and higher susceptibility effects. With the establishment of a specific examination protocol, ultrahighfield MR mammography at 7T was feasible with a higher spatial and a temporal resolution. The imaging results demonstrate its high diagnostic potential in revealing detailed anatomical and pathological features. The implementation of further advanced bilateral coil concepts is needed to circumvent current coil-related limitation, including suboptimal penetration depth, SAR limitations, and the inability to perform parallel imaging.

15:00         4133.     Parallel RF Transmission for Breast MRI at 3.0 Tesla: Preliminary Results

Christiane K. Kuhl1, Guido Kukuk, Juergen Gieseke1,2, Yvonne Mekes-Rijckaert2, Hans H. Schild1

1Radiology, University of Bonn, Bonn, Germ any; 2Philips Medical Systems, Best, Netherlands

Breast MRI at 3.0T has been shown to suffer from inhomogeneous RF transmission which results in heterogeneous T1-contrast across the field of view, in particular in large field-of-view, bilateral imaging protocols. The heterogeneous T1-contrast translates into variable enhancement of tumors, just depending on their location within the field of view. This has been a major reason why breast MRI at 3.0 T has only reluctantly been used in clinical practice. Breast Parallel RF transmission holds the promise of reducing dielectric resonance effects at high field strengths and enables control of RF distribution to optimize RF deposition. Parallel RF transmission has by now not been used or fully tested on clinical high-field MR systems. Our study demonstrates that parallel RF transmission in MR in breast imaging can effectively avoid B1-inhomogeneities.

 


 
Renal & Female Pelvis
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 66

14:00         4134.     Measuring Renal Function During Routine Clinical MR Exams: Is 5 Min Enough?

Jeff Lei Zhang1, Henry Rusinek1, Keyma Prince1, Hersh Chandarana1, David Stoffel1, Louisa Bokacheva1, Qun Chen1, Pippa Storey1, Vivian S. Lee1

1Radiology, New York University, New York, NY, USA

Glomerular filtration rate (GFR) measured by MR renography (MRR) is widely used in clinical practice for evaluating various renal diseases. MRR of short scan time has advantages of patient convenience and lower cost. Monte Carlo simulation and patient study were performed with different shortened scan time, and the precision and accuracy of the GFR estimates were compared with the reference values. The results showed that a low-dose MR renography scan time of less than 5 min appeared to be sufficient for GFR measurement.

14:30         4135.     Characteristics and Reproducibility of the Arterial Input Function (AIF) Derived from Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) Studies and Its Effect on Renal Functional Parameters

Marica Cutajar1,2, Iosif A. Mendichovszky3, Paul S. Tofts2, Isky Gordon1

1Radiology and Physics, UCL Institute of Child Health, London, UK; 2Brighton and Sussex Medical School, Brighton, UK; 3Imaging Science and Biomedical Engineering, University of Manchester, Manchester, UK

There are numerous publication in peer reviewed journals claiming that DCE-MRI can be used clinically to measure functional renal parameters. Review of the literature suggests that these claims are premature because of the large number of variables that must be taken into account. Most analysis of DCE-MRI use an arterial input function (AIF), there is no published work on either the reproducibility or the importance of the size and only a single publication on inter-observer reproducibility of AIF. This work is unique in having two DCE-MRI scans in the same healthy volunteer so that critical variables of the AIF can be assessed.

15:00         4136.     Measurement Accuracy of a Gadolinium Enhanced Magnetic Resonance Imaging Technique for the Measurement of Kidney Glomerular Filtration

Khalil Nabeel Salman1, Saravanan Kokila Krishnamoorthy1, Puneet Sharma1, Bobby Kalb1, Dana Tudorascu2, Diego R. Martin1

1Radiology, Emory University, Atlanta, GA, USA; 2Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA

Glomerular filtration rate (GFR) can be determined by MRI perfusion-filtration techniques using rapid volumetric perfusion imaging after administration of a filtered gadolinium-chelate. Several methods have been employed but there remains the need to increase the body of evidence validating each of the proposed models. We have been developing a methodology based on a 3-compartment kinetic model that accounts for the renal vascular, interstitial, and filtered compartments. In this study we compare the concurrent measurement of GFR by our MRI technique and by conventional creatinine-clearance technique in a series of patients. We show that the two methods are highly correlated.

15:30         4137.     Blade DCE MRI - Towards Renal Perfusion Measurements with Reduced Motion Artifacts

Florian Lietzmann1, Frank Zöllner1, Lothar Rudi Schad1

1Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany

The major problems in renal DCE MRI are, like in the entire field of abdominal imaging, motion artifacts that primarily arise from the patient´s respiration. Here, we present an approach utilizing Blade for DCE-MRI of the human kidney to suppress motion while keeping critical parameters like temporal and spatial resolution within acceptable limits.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 66

13:30         4138.     Towards Renal Compartment Segmentation Using an Unsupervised Neural Network Approach

Frank Gerrit Zöllner1,2, Lothar Rudi Schad1

1Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany; 2Section for Radiology, Department of Surgical Sciences, University of Bergen, Bergen, Norway

Dynamic contrast enhanced magnetic resonance imaging is an emerging technique for a more accurate assessment of local renal function. Automated methods mostly involves user interaction or are based on model assumptions.In this work we present a model free and unsupervised approach to renal compartment segmentation in 3D DCE-MRI data. Thereby self organizing maps (SOM)are utilized. Initial results demonstrate that SOMs could be used for a segmentation of the renal compartments but also, could give qualitative insights into local perfusion patterns of the kidney.

14:00         4139.     Automatic Estimation of Renal Cortical Thickness Using MRI Perfusion Curves

Luis Meneses1,2, Cristian Tejos2,3, Marcelo Andía1,2, Mario Fava1, Pablo Irarrazaval2,3

1Radiologia, Pontificia Universidad Catolica de Chile, Santiago, Metropolitana, Chile; 2Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile; 3Departamento de Ingenieria Electrica, Pontificia Universidad Catolica de Chile, Chile

We described a new semi-automatic method of segmentation to identify the renal cortex based on functional features of the kidney, using perfusion MRI data. By doing this we take advantage of the histological differences between kidney’s cortex and medulla. Our results show that we were able to differentiate both tissues. This have the potential utility to choose the most adequate treatment and for following-up patients after therapies.

14:30         4140.     Effect of Acute Hyperglycemia with Octreotide on Intra-Renal Oxygenation as Estimated by BOLD MRI in Rats

Lu-Ping Li1, Joann Carbray1, Sarah Halter1, Pottumarthi V. Prasad1

1Radiology, Northshore University Healthsystem, Evanston, IL, USA

Previous observations have shown lower intra-renal oxygenation early after induction of type I diabetes. In order to test the hypothesis that this may be related to direct effect of hyperglycemia, infusion of glucose solution was used in healthy rats. While a statistically significant but modest increase in R2* (and blood glucose) was observed, they were not comparable to those in diabetic rats. In this study, pretreatment with an insulin inhibitor (octreotide) was used to produce sustained and higher level of acute hyperglycemia in rats. Both blood glucose and R2* showed a significant and comparable increase to those in diabetic rats.

15:00         4141.     Monitoring Kidney Viability Before Transplantation by Means of 31P CSI and Oxygenated Hypothermic Perfusion

Francois Lazeyras1,2, Leo Buhler3, Jean-Paul Vallee1, Antonio Nastasi3, Raphael Ruttimann3, Philippe Morel3, Jean-Bernard Buchs3

1Service of Radiology, University of Geneva and University Hospital of Geneva, Geneva, Switzerland; 2Work supported in part by the Center for Biomedical Imaging (CIBM), Geneva and Lausanne, Switzerland; 3Visceral and Transplantation Service, University Hospital of Geneva, Geneva, Switzerland

The experimental studies presented in this paper show that ATP is resynthesized if kidneys are preserved with oxygenated hypothermic pulsatile perfusion (O2+HPP). The development of a MR compatible perfusion device allowed monitoring 31P spectra during continuous perfusion. Our results show that ATP reserve remains high if O2+HP is applied immediately after kidney harvesting. In this condition, PME remains elevated. In opposition, in absence of perfusion, gradual depletion of PME and limited resynthesis of ATP are observed. This technique may bring new insight for marginal organs reanimation and evaluation prior to transplantation.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 66

13:30         4142.     High Intense Myometrial Tumors on T2-Weighted Images: Differentiation with Diffusion-Weighted Imaging and 1H-MR Spectroscopy

Mayumi Takeuchi1, Kenji Matsuzaki1, Masafumi Harada2, Hiromu Nishitani1

1Department of Radiology, University of Tokushima, Tokushima, Japan; 2Department of Medical Imaging, University of Tokushima, Tokushima, Japan

We evaluated 37 myometrial tumors (7 malignant; 30 benign including 6 cellular and 24 degenerated leiomyomas) exhibiting high intensity on T2-WI. Differentiation based on the signal intensity was difficult. The ADCs in malignancies and leiomyomas were 0.79 +/- 0.26 and 1.54 +/- 0.35, respectively (p<0.01). The ADC in cellular leiomyomas was 1.18 +/- 0.16, which was significantly lower than that in degenerated leiomyomas (1.64 +/- 0.32) and higher than that in malignancies. MRS was performed in 4 malignancies and in 9 leiomyomas. High choline peaks were observed in all malignancies, and in one cellular leiomyoma showing rapid growth.

14:00         4143.     MR Manifestations of Hyperreactio Luteinalis: Value of Diffusion-Weighted Imaging in the Differentiation from Neoplastic Lesions

Mayumi Takeuchi1, Kenji Matsuzaki1, Hiromu Nishitani1

1Department of Radiology, University of Tokushima, Tokushima, Japan

We evaluated MR findings of 11 ovaries with hyperreactio luteinalis (HL) in 6 women (3 pregnant; 2 hydatid mole; 1 iatrogenic). Enlarged ovaries appeared as multilocular cystic masses with septations mimicking mucinous cystic tumors. Ovarian stroma was detected as small solid portion exhibiting intermediate intensity on T2WI, intense contrast-enhancement on Gd-T1WI, and high intensity on DWI like solid tumoral portion of neoplasms. The ADC in ovarian stroma in HL was 1.86 +/- 0.37, which was significantly higher than that in ovarian cancers (1.10 +/- 0.28, n=39) and may be a clue to the differential diagnosis.

14:30         4144.     Combined Use of T2-Weighted and Diffusion-Weighted 3T MR Imaging for Differentiating Uterine Sarcomas from Benign Leiomyomas

Tomohiro Namimoto1, Kazuo Awai1, Takeshi Nakaura1, Yumi Yanaga1, Tetsuo Saito2, Toshinori Hirai1, Yasuyuki Yamashita1

1Diagnostic Radiology, Kumamoto University, Kumamoto, Japan; 2Radiation Oncology, Kumamoto University, Kumamoto, Japan

To compare diagnostic ability of sole diffusion-weighted imaging (DWI) and DWI combined with T2-weighted MRI for differentiation of uterine sarcomas from benign leiomyomas. The mean apparent diffusion coefficient (ADC) value of sarcomas was 0.86 } 0.11~10-3mm2/s, which was significantly lower than that of leiomyomas 1.18 } 0.24~10-3mm2/s; however, there was a large overlap. Our preliminary results indicate that combined use of DWI and T2-weighted imaging was better than DWI or T2-weighted imaging alone in the differentiation of uterine sarcomas from benign leiomyomas.

15:00         4145.     Diffusion-Weighted (DW) Imaging in Ovarian Cystic Lesions: Value of DW Imaging Compared to T2-Weighted Imaging at 3T MRI

Tomohiro Namimoto1, Kazuo Awai1, Takeshi Nakaura1, Yumi Yanaga1, Shinichi Nakamura1, Tetsuo Saito2, Toshinori Hirai1, Yasuyuki Yamashita1

1Diagnostic Radiology, Kumamoto Universtiy, Kumamoto, Japan; 2Radiation Oncology, Kumamoto Universtiy, Kumamoto, Japan

The purpose of our study is to determine the usefulness of diffusion weighted (DW) imaging in the characterization of ovarian cystic masses and to clarify the relationship between the signal intensity in T2-weighted imaging and apparent diffusion coefficient (ADC) values at 3T MRI. Our study showed ADC values of endometrial cysts and mature cystic teratomas were significantly lower than those of other cystic lesions. However, the usefulness of the ADC values for differentiating benign from malignant cystic ovarian lesions was limited due to an influence from signal intensity of T2-weighted images with fat suppression.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 66

13:30         4146.     Susceptibility-Weighted Imaging for the Evaluation of Gynecologic Diseases

Mayumi Takeuchi1, Kenji Matsuzaki1, Hiromu Nishitani1

1Department of Radiology, University of Tokushima, Tokushima, Japan

We evaluated various gynecologic diseases by susceptibility-weighted imaging (SWI). Punctate or curved linear signal voids along the cyst wall due to hemosiderin deposition were characteristic for endometriomas, and were not be observed in non-endometrial benign cystic masses. SWI was also useful for the diagnosis of extra-ovarian endometriosis and adenomyosis by detecting hemosiderin deposition, of red degenerated leiomyoma at early phase by detecting intravenous deoxyhemoglobin, and of other pathologies with hemorrhage.

14:00         4147.     The Time-Course Effect of Anticholinergic Agents on Intestinal Motion and Uterine Peristalsis: Evaluation on Cine MRI

Sayaka Daido1, Asako Nakai1, Tomohisa Okada1, Toshikazu Kamae1, Koji Fujimoto1, Isao Ito2, Kaori Togashi1

1Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; 2Respiratory Medicine, Kyoto University Hospital, Kyoto, Japan

The purpose of this study is to evaluate the time-course effect of intravenously administrated anticholinergic agent on intestinal motion and uterine peristalsis, with the use of cine magnetic resonance (MR) imaging. 19 women in periovulatory phase underwent cine MR imaging before and 2-10 minutes after injection of an anticholinergic agent. Evaluations were performed by two radiologists.

14:30         4148.     Dynamic Contrast-Enhanced MRI of Cervical Tumors During Chemo-Radiation Correlated to Tumor Regression

Uulke A. van der Heide1, Catalina Arteaga de Castro1, Greetje Groenendaal1, Cornelis A.T. van den Berg1, Ina M. Jurgenliemk-Schulz1, Judith M. Roesink1

1Radiotherapy, UMC Utrecht, Utrecht, Netherlands

Dynamic contrast-enhanced MRI was used to monitor cervical tumors prior to and in the first four weeks of chemoradiation. An increase in Ktrans was observed in the first four weeks. Also Ktrans in the poorest perfused part of the tumor seems indicative for the rate of tumor regression.

15:00         4149.     DCE-MRI at 3T in Patients with Advanced Ovarian Cancer Undergoing Neo-Adjuvant Chemotherapy

Andrew Nicholas Priest1, Andrew B. Gill2, Masako Y. Kataoka1, Ilse Joubert1, Mary A. McLean3, Martin J. Graves1, John R. Griffiths3, Robin Crawford4, Helena Earl5, James Brenton3,5, David J. Lomas1, Evis Sala1

1Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, UK; 2Medical Physics, Addenbrookes Hospital, Cambridge, UK; 3Cambridge Research Institute, Cancer Research UK, Cambridge, UK; 4Obstetrics & Gynaecology,, Addenbrookes Hospital, Cambridge, UK; 5Oncology, Addenbrookes Hospital, Cambridge, UK

Ovarian cancer is a genetically heterogeneous disease with a poor prognosis, and treatment individualisation could be aided by an ability to predict treatment outcome e.g. through measurements reflecting tumour blood supply. This study reports measurements of dynamic contrast enhanced MRI before and after neo-adjuvant chemotherapy, in primary ovarian tumour, omental ‘cake’ and peritoneal deposits. A reduction in kep following treatment was found for ovarian and peritoneal tumours, with no change in the omental cake. There were no significant changes in Ktrans or area under the curve, possibly due to the small number of patients (14) studied so far.

 


 
Preclinical Cancer Studies
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 67

14:00         4150.     Silibinin Feeding Alters the Metabolic Profile in TRAMP Prostatic Tumors: A 1H-NMR Study

Natalie J. Serkova1, Komal Raina2, Andrea L. Merz1, Rajesh Agarwal2

1Anesthesiology, University of Colorado Health Sci, Aurora, CO, USA; 2Pharmaceutical Sciences, University of Colorado Health Sci, Aurora, CO, USA

The chemopreventive efficacy of silibinin (flavonolignan from milk thistle seeds) on prostate cancer metabolism was evaluated in TRAMP mouse model. Prostate tissues were obtained after 20-week silibinin diet and analyzed by quantitative 1H-NMRS. Multivariate principle component analysis (PCA) was applied for group separation and biomarker identification. The antitumor effect of silibinin is accompanied by alteration of the metabolic profile of the TRAMP biopsies as indicated by a 6-fold increase in the glucose content, 3-fold increase of citrate and a significant reduction in the lactate levels. A decrease in cholesterol and phosphatidylcholine was observed with silibinin feeding.

14:30         4151.     Pre-Clinical Evaluation of Anti-Angiogenic Agent RO0281501 on R3327 at Prostate Model Using Lactate MRS and DCE-MRI

Jadegoud Yaligar1, Sunitha B. Thakur1,2, Mihai Coman1, Mihaela E. Lupu1, Ya Wang1, Kenneth Kolinsky3, Brian Higgins3, Kristen L. Zakian1,2, Jason A. Koutcher1,4

1Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, USA; 2Radiology, Memorial Sloan-Kettering Cancer Center; 3Discovery Oncology, Hoffmann-La Roche, Nutley, NJ, USA; 4Medicine, Memorial Sloan-Kettering Cancer Center

Angiogenesis is critically mediated by endothelial cell receptor tyrosine kinase. Present study designed to study the anti-angiogenic effect of RO0281501 in R3327 AT rat prostate tumor model by MRS tumor lactate measurement and DCE-MRI. Post 24hr treatment tumor inhibition was 18 % and by day 7 it was 40 % (compared to control group). Treated group Akep (tumor rim) value at 24hrs is significantly (p<0.05) lesser than its baseline Akep value whereas reduction in Akep is not signficant in control group. Lactate detected prior to treatment has significantly (p<0.05) reduced after 24hr of treatment and increased significantly on day 7.

15:00         4152.     Comparison Between ADC and QSI-Derived Parameters Mapping and Early Effect of Radiation Therapy in a Rodent Tumour Model

Denis Rommel1, Frank Peeters1, Jorge Abarca-Quinones1, Vincent Gregoire2, Thierry Duprez1

1Medical Imaging, Université Catholique de Louvain, Brussels, Belgium; 2Center for Molecular Imaging and Experimental Radiotherapy, Université Catholique de Louvain, Brussels, Belgium

Q-space Imaging(QSI)-derived diffusion parameters could be more powerful in probing early micro-architectural disruption after radiation therapy (RT) than the ADC. 19 tumor xenografts in rats were examined before and three days after single-session external RT (14Gy). ADC maps at b=1000 were compared to mean value and fractional anisotropy maps for the height (RTO), width (FWHM), and kurtosis (k) of the Probability Density Function (PDF) through tensor analysis. ADC showed better sensitivity to early radiation-induced changes when compared to QSI-derived parameters. Assessment of the added value of QSI information in RT monitoring needs further investigation.

15:30         4153.     Proton Diffusion Weighted and Sodium MRI of Growing Intrahepatic and Subcutaneous Hepatocellular Carcinoma

Andriy Babsky1, Shenghong Ju1, Stacy Bennett1, Bharath Atthe1, Beena George1, Gordon McLennan1, Navin Bansal1

1Radiology, Indiana University, Indianapolis, IN, USA

Effects of untreated tumor growth on 1) water apparent diffusion coefficient (ADC), 2) single-quantum (SQ) 23Na MRI, and 3) triple-quantum-filtered (TQF) 23Na MRI were compared in intrahepatic (IH) and subcutaneous (SC) hepatocellular carcinoma (HCC) in rats. The ADC measurement of IH-HCC is very sensitive to physiological motion. The ADC increased progressively with growth in SC HCC but not in IH HCC. SQ and TQF 23Na MRI signals increased with growth in both the tumor models. SQ and TQF 23Na MRI techniques are more reliable compared to water ADC measurements for hepatic tumor studies because of their insensitivity to motion.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 67

13:30         4154.     Vascular Phenotyping of Brain Tumors with MR Microscopy (μMRI)

Arvind P. Pathak1, Jiangyang Zhang1, Melina Jones2

1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; 2Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA

The angiogenic phenotype of brain tumors is a critical determinant of their pathophysiology, efficacy of therapy and image contrast in MRI. While histological techniques such as optical microscopy are excellent for imaging microvasculature at the "cellular" scale, they suffer from limited coverage, and 3D blood vessel geometry once destroyed by sectioning requires complex reconstruction. In contrast, in vivo MRI with its sub-millimeter resolution has proved useful for obtaining angiogenic biomarkers such as blood volume and vessel size index at the "systemic" scale. Noninvasive techniques that enable characterization of the angiogenic phenotype at spatial resolutions intermediate to the "cellular" and "systemic" are scarce. Here we describe a new method for characterizing the angiogenic phenotype of a brain tumor model using magnetic resonance microscopy (μMRI), which in combination with different kinds of MR contrast can provide a wealth of information on the brain tumor microenvironment inaccessible by other imaging methods. The high-resolution 3D images of the vasculature generated by μMRI enabled us to characterize morphological differences between the angio-architecture of the contralateral brain and that of the tumor using fractal analysis.

14:00         4155.     Lesion Enhancement in a Rat Brain Tumor Model: Evaluation of 1 M Gadobutrol Vs Two Conventional Gadolinium Chelates, All Injected at a Dose of 0.1 Mmol/kg at 3T.

Ulrike Irmgard Attenberger1, Val M. Runge2, Carney B. Jackson3, Shannon S. Baumann2, Krista Birkemeier2, Henrik J. Michaely4, Stefan O. Schoenberg4, Maximilian F. Reiser1, Bernd J. Wintersperger1

1Department of Clinical Radiology, Munich University Hospitals - Grosshadern, Ludwig-Maximilians-University, Munich, Germany; 2Department of Radiology, Scott & White Clinic and Hospital, Texas A&M University Health Science Center, Temple, TX, USA; 3Veterinary Science, College of Agriculture, University of Kentucky, Lexington, Kenntucky, USA; 4Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim – University of Heidelberg, Mannheim, Germany

Seven gadolinium chelates have been approved in countries across the world for contrast enhanced MRI of the brain. These contrast agents are, with one exception, formulated at a concentration of 0.5 mmol/mL. Gadobutrol is a double concentrated non-ionic macrocyclic gadolinium chelate, with high in vivo stability. Combining a 1.0 M, high relaxivity, gadolinium chelate and 3 T offers multiple opportunities for further improvement of lesion enhancement. The aim of this study was to evaluate tumor enhancement in a rat brain glioma model comparing 1.0M gadobutrol and two standard 0.5 mmol/mL gadolinium chelates, all injected at the same dose.

14:30         4156.     Osteoblastic and Angiogenic Reactions in Prostate Cancer Bone Metastasis Models Studied by Macromolecular DCE-MRI and μCT

Hagit Dafni1, Andrew J. Burghardt1, Sharmila Majumdar1, Nora M. Navone2, Sabrina M. Ronen1

1Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; 2Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

Angiogenesis, osteolytic and osteoblastic reactions of prostate cancer bone metastases models were studied by in-vivo macromolecular DCE-MRI and ex-vivo μCT. The osteolytic model showed only peripheral extravasation of macromolecules whereas the osteoblastic model had leaky blood vessels throughout the tumor, probably due to stromal and structural support that maintain lower tumor intersitial fluid pressure. Osteolysis was detected in both models but osteogenesis was observed only in the osteoblastic one. Thus μCT indicates bone formation and resorption but macromolecular DCE-MRI also provides structural information, and serves as a method to monitor tumor interaction with stromal cells and response to antivascular treatment.

15:00         4157.     A Dual Modality System for Simultaneous Monitoring of a Bi-Functional Optical & MRI Contrast Agent for Cancer Detection

Yuting Lin1, Mehmet B. Unlu1, Brian Grimmond2, Anup Sood2, Egidijus E. Uzgiris3, Orhan Nalcioglu1, Gultekin Gulsen1

1Center for functional onco imaging, University of California, Irvine, CA, USA; 2GE Global Research, Niskayuna, NY, USA; 3Rensselaer Polytechnic Institute, Troy, NY, USA

Multi-modality imaging is becoming a trend in developing new generation in vivo imaging techniques for diagnosis. Recently, our group has developed a hybrid MRI/DOT multi-modality imaging system. In such a multi-modality system, each modality measures a different parameter set, which make it difficult to cross-validate the parameters measured by different modalities. An alternative solution is using a bi-functional contrast agent that provides contrast for both optical and MRI simultaneously. Here, our in vivo small animal study is the first to validate a true multi-modality system with a true multi-modality contrast agent.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 67

13:30         4158.     Lymph Node Volume and Apparent Diffusion Coefficient as a Biomarker for Metastatic Invasion in an Experimental Model

Wenche Margrethe Klerkx1, Albert Geldof2, Fredy Visser, Taro Takahara, Peter Luijten, Peter Heintz, Willem Mali, Wouter Veldhuis

1University Medical Center Utrecht, Utrecht, Netherlands; 2Urology, Free University of Amsterdam, Amsterdam

Detection of lymph node metastases is one of the most challenging fields in oncologic MR imaging. A straightforward and reproducible model for lymph node metastasis was developed in Copenhagen rats. MR imaging was performed every 3 days for 14 days after tumour cell implantation to assess lymph node growth and apparent diffusion coefficient (ADC) changes over time. ADC of metastatic lymph nodes decreased simultaneously with increasing volume, suggesting ADC might be a biomarker predicting tumour implantation and lymph node growth.

14:00         4159.     Advantages of Micron-Sized Magnetic Particles for Tracking Dendritic Cells in Preclinical Cancer Vaccine Studies

Roja Rohani1, Greg Dekaban2, Christy Willert2, Sonali De Chickera2, Paula Foster1

1Imaging, Robarts Research Institute, London, Ontario, Canada; 2Biotherapeutic, Robarts Research Institute, London, Ontario, Canada

Successful Tracking of Dendritic cells (DC) is crucial for better understanding of the fate of DC based cancer vaccines. In previous preclinical and clinical studies supreparamagnetic iron oxide (SPIO) particles were used as DC labels and the migration of DC were followed using cellular MRI. Here we show that micron-sized superparamagnetic iron particles (MPIO) enable the detection and quantification of migrating DC. Since MPIO are inert, have high iron content and are readily taken up by DC, they are a very good label for tracking small numbers of cells or cells with less iron content.

14:30         4160.     MRI/ MRS on Leukemia Development in MLL-AF9 Transgenic Mice

Deborah DeRyckere1, Margaret E. Macy1, Kendra M. Hasebroock2, Lori A. Gardner3, Paul Jedlicka4, Erica L. Bradshaw-Pierce2, Andrea L. Merz2, Lia Gore1, Natalie J. Serkova2

1Medical Oncology, University of Colorado Health Sci, Aurora, CO, USA; 2Anesthesiology, University of Colorado Health Sci, Aurora, CO, USA; 3Pediatrics, University of Colorado Health Sci, Aurora, CO, USA; 4Pathology, University of Colorado Health Sci, Aurora, CO, USA

We used T1-MRI and ex vivo MRS to evaluate changes in bone marrow, spleen and blood in leukemic MLL-AF9 transgenic (Tg) mice during disease progression. MLL-AF9 Tg mice exhibited a statistically significant 1.5 fold increased in bone marrow T1-weighted MR signal intensity. Increased glycolysis rates, increased 13C-glucose utilization, in addition to increased levels of glutathione and glycine were observed in Tg animals. Because increase in T1 intensities and metabolic changes preceded detectable increase in white blood cell count, MRI/MRS endpoints can be useful as early markers for leukemia development and response to therapies.

15:00         4161.     MR Characterization of Two Experimental Models of Ovarian Cancer: Metabolite Quantification and Diffusion and Perfusion Assessment

Rossella Canese1, Maria Elena Pisanu1, Alessandro Ricci1, Luisa Paris1, Carmela Rozera1, Massimo Spada1, Albino Cesolini1, Massimo Venditti1, Massimo Giannini1, Filippo Belardelli1, Egidio Iorio1, Franca Podo1

1Istituto Superiore di Sanità, Roma, Italy

Ovary cancer is the gynaecological malignancy at highest death rate. MRI combined with MRS has demonstrated its usefulness in tumour diagnosis, prognosis and treatment evaluation. In this work two models of human ovarian carcinoma were implemented and characterised by quantitative MRS and ADC measurements: 1) sc implantation in the dorsum and 2) ip implantation in the peritoneum of SKOV3ip cells in SCID mice. Both ortho and heterotopic ovarian cancer models gave reasonable values for tCho and Ino concentration as well as for ADCs and perfusion fractions and can represent valuable tools in the evaluation of new therapies.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 67

13:30         4162.     The Analysis of Lipid and Macromolecule Signals in HR-MAS Data Reveals Information on the Nature of Cytoplasmic Lipid Droplets

Martin Wilson1,2, Greg M. Reynolds3, Risto A. Kauppinen4, Theo N. Arvanitis2,3, Andrew C. Peet1,2

1Cancer Sciences, University of Birmingham, Birmingham, West Midlands, UK; 2Oncology, Birmingham Childrens Hospital Foundation Trust, Birmingham, West Midlands, UK; 3School of Electronic, Electrical & Computer Engineering, University of Birmingham, Birmingham, West Midlands, UK; 4Dartmouth Medial School, Dartmouth College, Hanover, NH, USA

A method is presented to investigate the signals originating from cytoplasmic lipid droplets (CLDs) and macromolecules present in 1H HR-MAS spectra. Data from a panel of 18 cell lines, derived from a range of childhood nervous system tumours, is analysed and strong correlations are found between lipid signals at 0.9. 1.3, 1.6 and 5.3ppm. Weaker correlations are also observed for the macromolecule peaks. The relative ratios between the lipid peaks are constant implying that CLD signals originate from a homogeneous group of species.

14:00         4163.     NMR Structural Characterization and Inhibition of Colon Cancer Cells by Components of Citrus Aurantium L.

G K. Jayaprakasha1, Jadegoud Yaligar2, G A. Nagana Gowda3, Bhimanagouda S. Patil1

1Horticultural Sciences, Vegetable & Fruit Improvement Center,Texas A&M University, College Station, Texas-77843, USA; 2Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York-10065, USA; 3Chemistry, Purdue University, West Lafayette, Indianapolis-47907, USA

Epidemiological data suggest that ingestion of some bioactive compounds from fruits and vegetables may contribute to reduction of cancer incidence in humans. Colon cancer is second leading cause of cancer deaths in US. Two bioactive compounds were isolated from sour oranges (Citrus aurantium L.) and their structure was unambiguously confirmed by 1D and 2D NMR analysis. Limonexic acid at 24h post treatment showed significant cytotoxic effect at low concentration as compared to untreated cells. However sitosterol glucoside showed significant cytotoxic effect only at 10.0 µM(p<0.05) concentration. Both compounds have ability to arrest DNA synthesis and G2/M phases of cell cycle.

14:30         4164.     A 1H NMR-Based Metabolomics Study of Cellular Senescence, Quiescence and Transformation

Basetti Madhu1, Masako Narita2, Masashi Narita2, John R. Griffiths1

1Molecular Imaging, Cancer Research UK Cambridge Research Institute, Cambridge, England, UK; 2Cellular Senescence & Tumour Suppressor Laboratory, Cancer Research UK Cambridge Research Institute, Cambridge, England, UK

Senescence, which is a permanent cell cycle arrest, is thought to act as a fail-safe mechanism to prevent the transformation of cells into malignant phenotypes; as a tumour suppressing mechanism it shares conceptual and therapeutic similarities with the apoptosis machinery. SA-β-gal activity, elevated p53 and p16 protein levels, coupled with morphological changes and gene expression, are used as senescence markers, though reliable metabolic markers for senescence are still required. We present a 1H NMR based metabolomics study of senescence induced by oncogenic Ras and etoposide-induced DNA damage, along with replicative senescence, quiescence and malignant transformation (by E1a/Ras) in HDFs

15:00         4165.     Changes in High Spectral and Spatial Resolution Images of Murine Mammary Tumors Due to the Introduction of Carbogen

Sean Foxley1, Marta Zamora1, Erica Markiewicz1, Gregory Karczmar1

1Department of Radiology, University of Chicago, Chicago, IL, USA

The purpose of this work was to investigate the effects of carbogen breathing in murine mammary tumors. Female SV40 TAg transgenic mice were imaged with high spectral and spatial resolution at 9.4T before and after the introduction of carbogen to the air supply. Images were produced from the peak of the water resonance in each tiny voxel and subtraction images were produced. The tumor rim and tumor center had similarly large positive and negative responses to the change in blood oxygenation due to the introduction of carbogen. Changes identified could be clinically useful for the development of improved treatment planning.

 


 
Tumor Therapy Response: Preclinical & Human Studies
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 68

14:00         4166.     Simple, Universal Phantom for Multi-Center Apparent Diffusion Coefficient (ADC) Measurement

Marko K. Ivancevic1,2, Charles R. Meyer3, Craig J. Galban2, Benjamin A. Hoff2, Thomas C. Kwee2, Brian D. Ross2, Thomas L. Chenevert2

1MRI, Philips Medical Systems, Cleveland, OH, USA; 2Radiology, University of Michigan, Ann Arbor, MI, USA; 3Radiology, University of Michgan, Ann Arbor, MI, USA

Quantitative biomarkers are being developed for tumor therapy response assessment where timely assessment of therapy response is extremely important. Diffusion-weighted MR imaging provides such a biomarker, the apparent diffusion coefficient (ADC) in a noninvasive manner. In order to estimate the accuracy of ADC as a biomarker and provide uniform quality assurance across multiple MR systems a reproducible phantom is needed. In this study ADC was measured in an ice-water phantom on multiple field strength MR scanners.

14:30         4167.     Monitoring Therapeutic Response in a Murine Model of Medulloblastoma Treated with a Small Molecule Inhibitor of Hedgehog Signaling

Bruno Alicke1, Christopher Callahan2, Ryan Ybarra3, Stephen Gould1, Joan Greve4

1Small Molecule Translational Oncology, Genentech, Inc.; 2Research Pathology, Genentech, Inc.; 3Mouse Genetics, Genentech, Inc.; 4Biomedical Imaging, Genentech, Inc., South San Francisco, CA, USA

Medulloblastoma is the most common malignant brain tumor in children. Although current standards of care have improved survival, approximately 1/3 of patients are not cured and current therapies are associated with significant morbidity. Therefore, alternative therapeutic approaches are strongly desired. Of particular interest are therapies that target molecular pathways shown to be deregulated in medulloblastoma, such as the hedgehog signaling pathway. These data show that MRI, when combined with pre-clinical pharmacokinetic data, may have utility for determining therapeutic dose and response in both preclinical and clinical settings.

15:00         4168.     Detection of Early Response to Proteasome Inhibitor Treatment in a Rat Glioma Model with Amide Proton Transfer (APT) Imaging

Jinyuan Zhou1,2, De-Xue Fu3, Tingting Zhou1, Bachchu Lal, John Laterra, Peter van Zijl1,2

1Department of Radiology, Johns Hopkins University, Baltimore, MD, USA; 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; 3Department of Oncology, Johns Hopkins University, Baltimore, MD, USA

Amide proton transfer (APT) imaging detects endogenous mobile proteins and peptides in tissue using the chemical exchange-dependent saturation transfer (CEST) sensitivity enhancement mechanism. We here show initial results demonstrating that APT has potential as an early marker for visualizing changes in cellular protein properties in vivo associated with tumor chemotherapy using proteasome inhibitors.

15:30         4169.     Differential Effects of VEGF-Trap on Benign and Malignant Human Melanoma Xenografts Evaluated by DCE MRI

HuaLei Zhang1, Hui Qiao1, Fabao Gao1, Karthik Raju1, Steven Pickup1, Xin Li2, Jerry Glickson1, Rong Zhou1

1Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA; 2Advanced Imaging Research Center,, Oregon Health & Science University, Portland, OR, USA

Based on our previous development of a DCE MRI protocol which permits simultaneous measurement in mice the arterial input function of gadodiamide and its uptake in tumor, here we evaluate the effect of an antibody to the vascular endothelia growth factor (VEGF), namely VEGF-Trap, on a highly metastatic and a non-metstic melanoma xenografted in mice. In A375P line, the VEGF-trap treated has a significant Ktrans reduction (p=0.029) in the periphery compared to IgG treated ones at the end of 3 weeks. The Ktrans is homogeneously reduced (p=0.028 comparing the periphery and centre Ktrans difference between VEGF-trap and IgG treatment.) in VEGF-trap group while periphery is higher than core in IgG group. In C8161 line, the reduction in tumor periphery exists but is not statistically significant comparing the VEGF-trap treated with the IgG treated.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 68

13:30         4170.     Multi-Parametric MR Imaging for Anti-Angiogenic Tumor Treatment Monitoring – a Preclinical Study

Janine Ring1, Stefanie Remmele2, Walter Heindel1, Thorsten Persigehl1, Christoph Bremer1

1Department of Clinical Radiology, University Hospital of Muenster, Muenster, Germany; 2Medical Imaging Systems, Philips Research Europe, Hamburg, Germany

Sensitive tools for early monitoring of anti-angiogenic tumor treatment are desired. Therefore, tumor bearing nude mice were treated with a multi-targeted tyrosine kinase inhibitor and investigated by USPIO enhanced “steady state” MRI and diffusion weighed imaging (DWI) before and after treatment. In response to therapy, the decrease in ÄR2*- and vessel size maps clearly visualized the decrease in blood supply and the ADC-maps showed a water diffusion increase, reflecting the reduced tumor tissue cellularity. Histological analysis confirmed the MR-results, underlining that multi-parametric MR imaging allows for anti-angiogenic tumor treatment monitoring by non-invasive visualization of tumor microvascular and cellularity changes.

14:00         4171.     Study of Regression of Breast Tumor in Mice Model Using MRI

Sanjay Annarao1, Preeti Singh2, Madan Madav Godbole2, Raja Roy1, C L. Khetrapal1

1Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2Department of Endocrinology, Sanjay Gandhi Post-graduate Institute of Medical Sciences, Lucknow, UttarPradesh, India

Therapeutic efficacy of the drug Chloroquine in breast tumor in mice model has been studied and the results are presented. The MRI studies involved examining the response of two different types of treatments, namely (a) oral administration of molecular Iodine and (b) molecular Iodine with chloroquine. The results indicate more decrease of the tumor size in combined treatment compare to the molecular iodine alone. Therefore, chloroquine in combination with molecular iodine appears to be a better as therapeutic efficacy as pointed out in-vitro studies.

14:30         4172.     Application of a Biodegradable Macromolecular Contrast Agent in Dynamic Contrast Enhanced MRI to Assess the Efficacy of Indocyanine Green Enhanced Photothermal Cancer Therapy

Yi Feng1,2, Eun-Kee Jeong3, Lyska Emerson4, Zheng-Rong Lu5

1Drug Developement, Nevada Cancer Institute, Las Vegas, NV, USA; 2University of Utah, Salt Lake City, UT, USA; 3Radiology, University of Utah; 4Pathology, University of Utah; 5Pharmaceutics and Pharmaceutical Chemistry, University of Utah

Biodegradable macromolecular contrast agents (BMCA) alleviate the high Gd(III) retention problem of macromolecular contrast agents by in vivo degradation while retaining their advantages over small molecular weight contrast agent in tumor imaging. Tumor bearing mice were treated by photothermal therapy enhanced by intratumoral injection of indocyanine green and subjected to DCE-MRI scan using (Gd-DTPA)-cystamine copolymers (GDCC, a BMCA) and Gd-(DTPA-BMA). Tumor vasculature parameters (two-compartment model) using GDCC significantly dropped 4 hr after treatment and returned to normal 7 days later. Parameters using Gd-(DTPA-BMA) were too high. GDCC is promising in timely and accurately evaluation of anti-cancer treatment using DCE-MRI.

15:00         4173.     Combined Macromolecular DCE-MRI and Hyperpolarized 13C MRSI Indicate an Association Between Vascular and Metabolic Effects of Imatinib in a Prostate Cancer Bone Metastasis Model

Hagit Dafni1, Peder E. Z. Larson1, Simon Hu1, Robert Bok1, Chris Ward1, Chunsheng Wang1, Lynn DeLosSantos1, Xiaoliang Zhang1, Daniel B. Vigneron1, Sabrina M. Ronen1

1Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA

Combined vascular and metabolic changes were detected in responses to 2-days imatinib (PDGFR inhibitor) and paclitaxel treatment of a bone metastases model (PC-3MM2). Macromolecular DCE-MRI, using albumin-GdDTPA, indicated decrease in vascular permeability and 13C-MRSI, using hyperpolarized pyruvate, indicated reduced lactate signal. Immunohistochemistry suggested HIF-1 as a connecting link, as HIF-1 is regulated by receptor tyrosine kinases (i.e. PDGFR) signaling and controls both LDH (catalyzes pyruvate to lactate conversion) and VEGF (involved in the vascular response to imatinib, as we showed previously). Thus, combining DCE-MRI, hyperpolarized 13C-MRSI and immunohistochemistry can help reveal the mechanism and identify biomarkers of response to treatment.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 68

13:30         4174.     Quantitative DCE-MRI and Positron Emission Tomography (PET) for Assessment of Treatment Response in a Mouse Xenograft Model of Colorectal Cancer

Erica Lynn Bradshaw-Pierce1, Kendra M. Hasebroock, Andrea L. Merz, John J. Tentler2, S Gail Eckhardt2, Natalie J. Serkova

1Anesthesiology, University of Colorado Denver Health Sciences Program, Aurora, CO, USA; 2Medical Oncology, University of Colorado Denver Health Sciences Program

Quantitative DCE-MRI and PET endpoints were used to assess therapeutic efficacy of two different signal transduction modulators in a mouse model human cancer. Tumors responded well to one of the agents and only modestly to the other. We show utility of DCE-MRI and PET to evaluate the anti-angiogenic and metabolic activity of highly responsive tumors. Our data also shows that DCE-MRI and PET did not provide any indication of moderate therapeutic response, as our “non-responsive” agent managed to reduce tumor volume by 45% compared to control. Additionally, we found that the total tumor volume negatively correlates with Gd-uptake kinetics.

14:00         4175.     Hemodynamic Response Imaging for the Assessment of Anti-Angiogenic Treatment Response

Yifat Edrei1,2, Eitan Gross3, Natalie Corchia1, Eli Pikarsky4, Shmuel Ben-Sasson5, Rinat Abramovitch1,2

1The Goldyne Savad Inst. for Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 2MRI/MRS lab HBRC, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 3Pediatric Surgery, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 4Department of Pathology, Hadassah Hebrew University Medical Center, Jerusalem, Israel; 5Experimental Medicine & Cancer research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel

The ability to detect early effects of tumor therapeutic-response could facilitate therapy-continuation decisions. Since anti-angiogenic therapy may not lead to substantial tumor-mass reduction, conventional tumor-size measurements may be insensitive. Recently, we demonstrated the feasibility of Hemodynamic Response Imaging (HRI; fMRI combined with hypercapnia and hyperoxia) for monitoring liver perfusion. We assessed the therapeutic effects of a novel anti-angiogenic therapy in colorectal-liver-metastases model by HRI. The treatment reduced tumor growth, but, it induced a change in the growth-morphology which was reflected in HRI maps. Thus, HRI offers a new method for monitoring anti-angiogenic therapy-response and may facilitate detection of tumor deterioration.

14:30         4176.     Gemcitabine Uptake in Transplanted and Primary Pancreatic Ductal Adenocarcinoma: A 19F MRS Study

Basetti Madhu1, Kenneth P. Olive2, Mae A. Goldgraben2, David A. Tuveson3, John R. Griffiths1

1Molecular Imaging, Cancer Research UK Cambridge Research Institute, Cambridge, England, UK; 2Tumour Modelling & Experimental Medicine , Cancer Research UK Cambridge Research Institute, Cambridge, England, UK; 3Tumour Modelling & Experimental Medicine, Cancer Research UK Cambridge Research Institute, Cambridge, England, UK

Pancreatic ductal adenocarcinoma (PDA) is profoundly insensitive to treatment with a broad variety of chemotherapeutic regimens but occasionally responds to gemcitabine (difluoro-deoxycytidine, dFdC). Tuveson and colleagues developed a genetically engineering mouse model of PDA that recapitulates the cardinal pathophysiological and molecular features of the cognate human disease. We have used 19F MR spectroscopy to follow the uptake of gemcitabine and formation of its active compound dFdCTP in primary and transplanted tumours of PDA and other tissues. Our data suggests that drug delivery and/or drug metabolism are critical features that influence the response to gemcitabine and potentially other agents in PDA.

15:00         4177.     Therapeutic Effect of Bleomycin and Doxorubicin on Skin Tumors: Assessment by MRI

Moganty Raja Rajeswari1, Uma Sharma1, N. R. Jagannathan2, Ashok Sharma1

1Biochemistry, All India Institute of Medical Sciences, New Delhi, Delhi, India; 2Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India

We used MRI to study the pharmacodynamics of bleomycin and doxorubicin on squamous cell carcinoma (SCC) of skin in mice, in order to get insights of prognosis and treatment strategies. Using MRI parameters, tumor volume, proton relaxation times, T1 and T2, we demonstrate the higher potency of doxorubicin as compared to bleomycin in treating skin tumors of SCC origin.. Results were further corroborated with biochemical parameters like proliferation and apoptotic index. Therefore study highlights the potential of MRI in detecting the efficacy or the resistance of anticancer drug on skin tumors.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 68

13:30         4178.     Is Serial MR Spectroscopy Revealing an Anti-Tumor Effect of Cediranib in Human Glioblastoma?

Heisoog Kim1,2, Ciprian Catana2, Eva-Maria Ratai2, Wei-Ting Zhang2, Priscilla Yeo2, Ovidiu Cristian Andronesi2, Tracy T. Batchelor3, Rakesh K. Jain4, A. Gregory Sorensen2

1NSE/HST, Massachusetts Institute of Technology, Cambridge, MA, USA; 2Radiology, Massachusetts General Hospital, Boston, MA, USA; 3Neurology, Massachusetts General Hospital, Boston, MA, USA; 4Radiation Oncology, Massachusetts General Hospital, Boston, MA, USA

This study evaluated the predominant metabolites’ changes in 1H-MRS to provide supplementary information understanding the response of cancerous tissue to the anti-angiogenic agent in patients with recurrent malignant glioblastoma. After one dose, NAA/norCre and Cho/norCre in eleven positive-responding patients showed a significant increase in ET. Also, NAA/norCre and Cho/norCre measured in all twenty patients showed significant changes at day 28, and at day 112, the trend was reversed, an increase of Cho and a decrease of NAA. By evaluating the early changes in the predominant metabolites, it would reveal a pharmacologic effect of cedrinib.

14:00         4179.     Evaluation of Diffusion Parameters as Early Biomarkers of Response to Therapy in High-Grade Gliomas

Inas Khayal1,2, Trey Jalbert1, Adam ElKhaled1, Susan M. Chang3, Soonmee Cha, Sarah J. Nelson1,2

1Surbeck Laboratory of Advanced Imaging, Department of Radiology, University of California, San Francisco, San Francisco, CA, USA; 2UCSF/UCB Graduate Group in Bioengineering, University of California, San Francisco, San Francisco, CA, USA; 3Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA

Key to the interpretation of diffusion parameters as early predictors or response to therapy is a comparison between parameters in similar regions of tissue in the pre-treatment and follow-up scans. This can be problematic when there is an extensive surgical resection, which leaves a relatively small region of residual tumor and which may lead to substantial tissue shift. The goal of this study was to evaluate the differences in diffusion parameters for patients showing clinical progression or short term radiographic response using pre-, mid- and post-RT scans for patients who had their initial surgery and adjuvant therapy at UCSF.

14:30         4180.     Clinical Potential of Absolute Concentration of Total Choline in Breast Cancer Patients Using In-Vivo Proton MR Spectroscopy: Assessment of Early Therapeutic Response Following Neo-Adjuvant Chemotherapy.

Rani Gupta Sah1, Uma Sharma1, Rajinder Parshad2, Naranamangalam R. Jagannathan1

1Department of NMR and MRI Facility, All India Institute of Medcial Sciences, New Delhi, Delhi, India; 2Department of Sugical Disciplines, All India Institute of Medcial Sciences, New Delhi, Delhi, India

The clinical potential of sequential monitoring of total choline (tCho) concentration using in-vivo proton MRS in the assessment of the therapeutic response of locally advanced breast cancer patients (n=17) undergoing neo-adjuvant chemotherapy (NACT) was evaluated. In 11 responders, tCho concentration before therapy was 4.8 ± 2.4 mmol/kg, which reduced to 2.6±1.6 (p<0.05) after I NACT and further to 1.7±0.9 and 0.4±0.1 after 2nd and 3rd cycle. In 6 non-responders, tCho concentration before therapy was 2.1 ± 0.9 mmol/kg and remained same after III NACT (2.1± 2.6 mmol/kg). Our MR data showed promise for early detection of tumor response to therapy.

15:00         4181.     Preliminary Experience with 3D DCE-MRI Evaluation of Children Treated for Osteosarcoma with Chemotherapy Plus Bevacizumab

Wilburn E. Reddick1, Junyu Guo1, Qing Ji1, John O. Glass1, Mary E. McCarville2, Najat C. Daw3

1Translational Imaging Research, St. Jude Children's Research Hospital, Memphis, TN, USA; 2Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, USA; 3Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA

We evaluated feasibility of DCE-MRI to assess the effect of chemotherapy and bevacizumab on tumor in six children treated for osteosarcoma. Bevacizumab is given three days before the first cycle of chemotherapy (day-3) and on the first day of subsequent cycles. DCE-MRI was performed at baseline, day-2, day+1, day+5, week5, and week10 before definitive surgery. Ktrans and ve did not change substantially for the initial two time points, but kep increased after bevacizumab alone on day-2 and day+1 then decreased during chemotherapy on day+5. DCE-MRI assessment of tumor changes during neoadjuvant chemotherapy and bevacizumab shows promising results for further investigation.

 


 
Abdominal Cancers: Diagnosis & Tumor Therapy Response in Humans & Animal Models
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 69

14:00         4182.     Prostate DCE-MRI with a 16-Channel Surface Array and Endorectal Coil Using Slice Oversampling and SENSE to Minimize Blood Inflow Effect

Marcelino Bernardo1,2, Yuxi Pang3,4, Baris Turkbey2, Raphael Alford2, Vijay Shah2, Ahmed M. Gharib5, Peter Choyke2

1Imaging Physics, SAIC-Frederick, Inc., Frederick, MD, USA; 2Molecular Imaging Program, National Cancer Institute, Bethesda, MD, USA; 3Philips Medical Systems, Cleveland, OH, USA; 4Molecular Imaging Program,, National Cancer Institute, Bethesda, MD, USA; 5NIDDK, Bethesda, MD, USA

To overcome blood inflow effect in accurately determining the arterial input function from the femoral artery in prostate DCE-MRI, we have performed a preliminary study on two patients to evaluate four-fold slice oversampling with SENSE using the 16-channel anterior half of a 32-channel cardiac array in combination with an endorectal coil. The thicker excitation slab provides for a more accurate determination of the contrast agent concentration in the blood which should provide for more consistent pharmacokinetic parameters across patients but there is a factor of two loss in temporal resolution. The addition of the posterior half and a dual element endorectal coil should improve SENSE performance.

14:30         4183.     Magnetic Resonance Imaging of the Prostate Using a 32 Channel Vs. an 8 Channel Coil at 3T

Steffen Sammet1, Guang Jia1, Jiachao Liang1, Francisco Aguila1, Seongjin Choi1, Jun Zhang1, Michael Vincent Knopp1

1Department of Radiology, The Ohio State University, Columbus, OH, USA

Magnetic Resonance Imaging (MRI) of the prostate is gaining increasing importance in diagnosis, characterization and therapy planning. This study objectively assesses imaging performance of a newly available, commercial 32 channel coil system vs. a standard 8 channel coil system for prostate MRI in-vivo at 3T. Prostate MR imaging at 3T using a 32 channel coil revealed substantially improved image quality, both quantitatively and qualitatively, compared to an 8 channel coil used under identical conditions and in an intra-individual comparison. Using coils with a higher number of elements appear to help overcome some of the challenges of high field MR body applications.

15:00         4184.     Evaluation of STIR-HASTE Whole Body MRI for the Initial Staging of Paediatric Lymphoma: A Correlation with PET/CT

Shonit Punwani1, Steve Bandula2, Vineet Prakash2, Alan Bainbridge2, Enrico De Vita1,2, Nicola Stevens2, Stuart Taylor1,2, Sharon Hain2, Stephen Daw2, Ananth Shankar2, Paul Humphries2

1University College London, London, UK; 2University College London Hospital, London, UK

Staging of childhood lymphoma uses serial PET/CT and chest CT examinations which deliver a high radiation burden to the patient. Whole body MRI using turbo spin echo images can be performed within 20-25 minutes and may provide a non-ionising method of disease evaluation. This study evaluates STIR-HASTE MRI against an 'enhanced' PET/CT standard for the initial staging of paediatric lymphoma.

15:30         4185.     Multiparametric Comparison of Magnetic Resonance Spectroscopy and Dynamic Contrast Enhanced Magnetic Resonance Imaging with Surgical Pathology

Daniel Jason Aaron Margolis1, Daisy Chien2, Ana Gomez, Gerhard Laub2, Timothy McClure1, Rajakumar Nagarajan1, Seong Ra3, Albert Thomas1, J. Paul Finn1, Steven Raman1

1Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; 2Siemens Medical Systems; 3Department of Pathology, David Geffen School of Medicine at UCLA, Los Angeles, CA

Prostate magnetic resonance spectroscopy (MRS) and imaging with dynamic contrast enhancement (DCE) is gaining favor as method for staging prostate cancer. This study serves to determine how well each component, and how well overall, prostate MRI localizes disease within the prostate by sextant location. A combination of T2WI, ADC and washout is the most accurate, but T2WI, ADC, and percent enhancement yields fewer false positives.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 69

13:30         4186.     DCE-MRI Evaluation of the Temporal Evolution of Bevacizumab Induced Anti-Vascular Effects in Colorectal Cancer Liver Metastases

James P. O'Connor1,2, Gordon C. Jayson2, Alan Jackson1, Chris J. Rose1, Claire L. Mitchell2, Yvonne Watson1, Caleb Roberts1, Sue Cheung1, Giovanni A. Buonaccorsi1, Andrew R. Clamp2, Jurgees Hasan2, Lynn Hope2, Karen Davies1, Olivia del Puerto3, Geoff J. Parker1

1Imaging Science & Biomedical Engineering, University of Manchester, Manchester, UK; 2Medical Oncology, Christie Hospital, Manchester, UK; 3Roche Products Ltd, Welwyn Garden City, UK

We provide comprehensive data to define the sequence, magnitude and duration of anti-vascular effects induced by bevacizumab in a study of patients with colorectal cancer liver metastases evaluated using DCE-MRI. We demonstrate statistically signifcant reduction in blood plasma volume and enhancing fraction within 48 hours that lead to resolution of oedema and tumour shrinkage. The study highlights the importance of (1) optimising measurement timing in quantitative imaging studies employed in clinical trials and (2) performing multi-parameter DCE-MRI data analysis.

14:00         4187.     Accuracy of USPIO-Enhanced MRI for Staging of Rectal Cancer: A Multicenter Study in an Expert an 3 Regional Centers

Monique Maas1, Geerard L. Beets2, Max J. Lahaye1, Sanne ME Engelen2, Jo PM Dohmen3, Godelieve RJ Opdenakker4, Doenja MJ Lambregts1, Joachim E. Wildberger1, Regina GH Beets-Tan1

1Radiology, University Hospital Maastricht, Maastricht, Netherlands; 2Surgery, University Hospital Maastricht, Maastricht, Netherlands; 3Radiology, St. Jans Gasthuis, Weert, Netherlands; 4Radiology, Laurentius Hospital, Roermond, Netherlands

14:30         4188.     Accuracy of Gadofosveset Enhanced MRI for Predicting Nodal Status in Primary Rectal Cancer

Doenja MJ Lambregts1, Geerard L. Beets2, Alfons G. Kessels3, Max J. Lahaye1, Sanne ME Engelen2, Monique Maas1, Adriaan P. de Bruïne4, Jan L. Verwoerd5, Tim Leiner1, Joachim E. Wildberger1, Regina GH Beets-Tan1

1Radiology, University Hospital Maastricht, Maastricht, Netherlands; 2Surgery, University Hospital Maastricht, Maastricht, Netherlands; 3Epidemiology, University Hospital Maastricht, Maastricht, Netherlands; 4Pathology, University Hospital Maastricht, Maastricht, Netherlands; 5Philips Healthcare, Eindhoven, Netherlands

 

15:00         4189.     The Therapy Response Monitoring by DCE-MRI in Primary Liver Cancers

David H. Gultekin1,2, William R. Jarnagin3, Jason A. Koutcher1, Mithat Gonen4, Dana Haviland3, Leslie H. Blumgart3, Michael I. D'Angelica3, Yuman Fong3, Ronald P. DeMatteo3, Nancy E. Kemeny5, Lawrence H. Schwartz2

1Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; 2Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; 3Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; 4Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; 5Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA

The role of DCE-MRI has been evaluated in a Phase II clinical study for the assessment of response to therapy in patients with unresectable primary liver cancers, hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), undergoing regional chemotherapy through continuous hepatic arterial infusion (HAI) treatment procedure.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 69

13:30         4190.     Assessment of the Antiangiogenic Therapy of Avastin in an Animal Colon Cancer Model with DCE-MRI and a Biodegradable Macromolecular Contrast Agent

Xue-Ming Wu1, Rongzuo Xu1, Eun-Kee Jeong2, James N. Lee3, Zheng-Rong Lu1

1Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, USA; 2Department of Radiology, University of Utah, Salt Lake City, ,Utah, USA; 3Center for Advanced Medical Technologies, Radiology Department, University of Utah, Salt Lake City, UT, USA

This study evaluated the efficacy of biodegradable macromolecular contrast agent, Gd-DTPA cystamine copolymer (GDCC), for quantitative assessment of the therapeutic efficacy of an antiangiogenic agent Avastin® in an animal tumor model. Tumor vascular parameters were estimated from DCE-MRI data of GDCC and a low molecular weight control agent before and after the treatment. The vascular parameters estimated from DCE-MRI with GDCC correlated well to tumor grow, while the parameters from Gd(DTPA-BMA) could not correlate tumor growth. The biodegradable macromolecular contrast agent has a potential for monitoring therapeutic efficacy of anti-angiogenic therapeutics.

14:00         4191.     Evaluating Acute Response to the Novel HIF Inhibitor NSC-134754 in an Orthotopic Prostate Tumour Model by MRI

Lauren CJ Baker1, Simon Walker-Samuel1, Jessica K. Boult1, Yann Jamin1, Margaret A. Ashcroft2, Simon P. Robinson1

1The Institute of Cancer Research, Sutton, Surrey, UK; 2Division of Medicine, University College, London, UK

Hypoxia-inducible factor-1 (HIF-1) is recognised as a key player in tumour cell adaptation to the hypoxic microenvironment. Putative HIF inhibitors are currently under investigation, and methods for assessing tumour response pursued. NSC-134754 was recently identified as a novel HIF-1 inhibitor which has efficacy in vivo. In this study, and for the first time, MR imaging biomarkers were used to assess acute response to NSC-134754 in vivo. Alterations in Ktrans , ADC and baseline R2* were apparent, though not significant. Given the complexity of the HIF pathway it is proposed that novel HIF inhibitors exhibit distinct, tumour-specific, time-dependent modes of effect.

14:30         4192.     Elucidating the Relationship Between ADC Measures of Cellularity and [18F]FLT-PET Indications of Cellular Proliferation in a Multimodal Imaging Study of Treatment Response

Shelby Katherine Wyatt1,2, Kevin Wilson1, Tuhin Kumar Sinha1,2, H. Charles Manning1,2, Thomas E. Yankeelov1,2, Robert J. Coffey3,4, John C. Gore1,2

1Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; 2Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; 3Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; 4Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA

The relationships between imaging biomarkers from different modalities and

15:00         4193.     Dynamic Contrast-Enhanced MR Imaging for Early Detection of Vascular-Permeability Changes Following Combination Therapy with Anti-EGFR Antibody and Irinotecan in Orthotopic Pancreatic Tumor Xenografts: A Pilot Study

Hyunki Kim1, Karri Folks1, Lingling Guo2, James George2, Jeffrey Sellers3, Donald Buchsbaum4, Kurt Zinn1

1Radiology, University of Alabama at Birmingham, Birmingham, AL, USA; 2Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; 3Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA; 4Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, USA

DCE MR imaging was applied for pancreatic tumor xenografts implanted in SCID mice orthotopically, detecting a significant therapeutic response in 3 days after anti-EGFR antibody and irinotecan administration. The early Ktrans decrease responsive to therapy was well correlated with tumor-growth suppression and bioluminescence-signal decrease over the 6 days of treatment. Therefore, DCE-MRI may be a reasonable approach to determine individualized tumor response against anti-EGFR antibody and/or irinotecan in clinical trials.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 69

13:30         4194.     Early Detection of Radiation Response in Non-Hodgkin’s Lymphoma Xenografts

Seung -Cheol Lee1, Tim Jenkins2, Stephen Pickup1, Harish Poptani1, Edward J. Delikatny1, Jerry David Glickson1

1Dept of Radiology, University of Pennsylvania, Philadelphia, PA, USA; 2Dept of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA

Non-invasive detection of early treatment response is very important as it can provide information of response to specific drugs/treatment and tailor-fit treatment for individual patients. Previously we have shown in a human NHL xenograft model that lactate detected by in vivo MRS can be used as a very early marker of response to CHOP chemotherapy. As radiation therapy is also commonly used as a therapeutic regimen in NHL, we tested in vivo MRS and MRI methods to determine if the MR indices can be used as early markers of response to radiation therapy in an NHL xenograft.

14:00         4195.     Multifunctional Microspheres with an Ultrahigh Holmium Load for Imaging and Therapy

Wouter Bult1, Peter Roland Seevinck2, Gerard C. Krijger3, Chris J.G. Bakker2, Wim E. Hennink4, Alfred D. van het Schip, Johannes Frank Nijsen5

1Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, Netherlands; 2Imaging Sciences Institute, UMC Utrecht, Netherlands; 3Reactor Institute Delft, TU Delft; 4Department of Pharmaceutics, Utrecht University, Netherlands; 5Department of Radiology and Nuclear Medicine, UMC Utrecht, Netherlands

Holmium loaded particles with an ultrahigh holmium load were developed. These particles were characterized chemically and the multimodality imaging behavior of the particles was investigated, both in vitro as well as ex vivo. The particle size was easily adapted, and therefore the particles are not only very suitable for radioablation of tumors, but also as a contrast agent for visualisation of tumors. Therefore we conclude that we have developed a versatile particle for both imaging and therapy.

14:30         4196.     A Method for MR Imaging of Prostate Cancer Patients in the Radiotherapy Treatment Position Without Loss of Image Quality

Scott Hanvey1, John Foster2, Martin Glegg1

1Beatson West of Scotland Cancer Centre, Glasgow, UK; 2Glasgow Cardiac Magnetic Resonance Unit, Western Infirmary, Glasgow, UK

Imaging prostate cancer patients in the radiotherapy treatment planning position using MRI is desirable, since MR image registration with CT in different positions introduces errors, which can result in inaccuracies in the delineation of the target volume. Positioning patients in the treatment position using a flat table is not possible in MRI without incurring an unacceptable loss in image quality as posterior imaging coils integrated within a flat table are not available. This study describes a method for MR imaging of prostate cancer patients in the radiotherapy treatment position while maintaining the image quality necessary for successful radiotherapy treatment planning.

15:00         4197.     Registration of Magnetic Resonance Images of the Prostate Obtained with an Endorectal Coil to Histological Sections

Yousef Mazaheri1, Oguz Akin2, Amita Shukla-Dave1, Daniel Chamudot1, Liang Wang2, Joanna Grater1, Samson W. Fine3, Victor Reuter3, Jason A. Koutcher1, Hedvig Hricak2

1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 2Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 3Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA

We present a 2D semiautomatic nonrigid registration method to co-register in vivo MR images of the human prostate to corresponding sections from whole-mount step-section pathology after radical prostatectomy.

 


 
Cancer Therapy Response
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 70

14:00         4198.     Evaluation of Vascular and Metabolic Response in a Human Breast Cancer Model Treated with Docetaxel

Line Rørstad Jensen1, Else Marie Huuse1, Tone Frost Bathen1, Pål Erik Goa2, Steinar Lundgren1,3, Ingrid Susann Gribbestad1

1Dept. of circulation and medical imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Dept. of radiology, St. Olav's University Hospital, Trondheim, Norway; 3Dept. of oncology, St. Olav's University Hospital, Trondheim, Norway

Methods like DCE-MRI and MRS are valuable methods for evaluating treatment effects in handling of cancer. In this study we have investigated changes after treatment with docetaxel in human MCF7 breast xenografts. Perfusion parameters were assessed by DCE-MRI and the metabolic pattern by in vivo MRS and ex vivo HR MAS MRS, followed by multivariate analysis. This anti-microtubule drug led to an increase in perfusion parameters in the treated groups. Furthermore, in vivo MRS and HR MAS MRS revealed a significant decrease in choline levels, and a shift to more normalized metabolic pattern in the treated groups.

14:30         4199.     In Vivo and Ex Vivo Choline Metabolite Profiles as Biomarkers for Treatment Response in Locally Advanced Human Breast Cancer

Mariann Gjervik Heldahl1, Beathe Sitter1, Tone Frost Bathen1, Maria Dung Cao1, Steinar Lundgren1,2, Ingrid Susann Gribbestad1

1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, N\A, Norway; 2Department of Oncology, St. Olavs University Hospital, Trondheim, Norway

New biomarkers are needed to obtain more individualized patient treatment. The objective of this study was to investigate the effect of neoadjuvant chemotherapy on the level and composition of choline compounds in human breast cancer using ex vivo HR MAS and in vivo MRS. The Cho, GPC, PC and tCho metabolite concentration showed differences between responders and non-responders both before and after neoadjuvant chemotherapy. These findings were most detailed in HR MAS spectra.

15:00         4200.     Alteration of Fibroglandular Tissue Volume and Contrast Enhancements Measured by MRI in the Normal Breast of Patients Receiving Neoadjuvant Chemotherapy

Jeon-Hor Chen1,2, H-J Yu1, S Bahri1, C-C Hsu2, F-T Hsu2, H-N Shih2, M-C Lin1, K Nie1, O Nalcioglu1, M-Y Su1

1Center for Functional Onco-Imaging, University of California Irvine, Irvine, CA, USA; 2Department of Radiology, China Medical University Hospital, Taichung, Taiwan

An MRI-based method was used to measure the percent breast density and enhancement kinetics in the normal breast of patients receiving neoadjuvant chemotherapy. Patients with higher baseline percent breast density were more likely to show a higher reduction of breast density. The mechanism may be due to the higher vascular supply associated with the higher density, which allows more delivery of chemo-regimens to the normal tissue, hence causes more damage and a higher reduction of the fibroglandular tissue. The reduced enhancement kinetics in follow-up MRI studies in the premenopausal women may be associated with damaged vessels thus lower vascular supply.

15:30         4201.     Multiparametric MRI/MRS and Gene Expression Profiling for Monitoring Docetaxel Effects in MCF7 Xenografts

Else Marie Huuse1, Line Rørstad Jensen1, Pål Erik Goa1,2, Steinar Lundgren1,3, Endre Anderssen4, Tone Frost Bathen1, Ingrid Susanne Gribbestad1

1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Department of Radiology, St. Olavs University Hospital, Trondheim, Norway; 3Department of Oncology, St. Olavs University Hospital , Trondheim, Norway; 4Department of Cancer Research and Molecular Medicine, NTNU, Trondheim, Norway

Sensitive methods are needed to assess early tumor response and obtain individualized treatment based on biological characterization of tumors. DCE-MRI, ADC-mapping and in vivo MRS combined with gene expression of tissue samples and multivariate data analysis, have been used to study changes during tumor progression and early effects of docetaxel in MCF7 xenografts. Our findings indicate that docetaxel treatment cause a significant increase in water diffusion, a significant change in v_e and distinct differences in the in vivo metabolite and gene expression profiles of controls and docetaxel treated tumors.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 70

13:30         4202.     Single-Dose X-Ray Irradiation Changes Significantly Tumor Perfusion, as Measured by In Vivo DCE 1H MRI

HyungJoon Cho1, Ellen Ackerstaff1, Matthew Kaag2, Mihai Coman1, Jason A. Koutcher1

1Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; 2Dept. of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA

Applying a priming dose of radiation to radioresistant, hypoxic tumors may be associated with reoxygenation of previously hypoxic areas and increased tumor radiosensitivity. Here, we assess in the radioresistant MCa tumor the effects of single high-dose irradiation on tumor perfusion as a function of time after irradiation. Single high-dose X-ray irradiation reduced tumor perfusion in the short term whereas 24h postirradiation tumor perfusion increased which may be indicative of reoxygenation. DCE MRI may be a valuable tool to evaluate the window of increased radiation sensitivity after priming radioresistant tumors with a single high dose of radiation.

14:00         4203.     Simultaneous Blood Volume and Vessel Size Imaging Technique for Localized Therapy Response Detection

Stefanie Remmele1, Julien Sénégas1, Thorsten Persigehl2, Christoph Bremer2, Janine Ring2

1Philips Research Europe, Hamburg, Germany; 2Department of Radiology, University of Muenster, Muenster, Germany

In this work, we present a technique for time-efficient and accurate relaxometry that allows for comprehensive multi-parametric and localized insight into vascularization changes in tumor therapy follow-up studies using blood-pool agents. In a preclinical study, the response to an anti-vascular treatment was only poorly reflected by global statistical values, but manifested in how vascularization distributed over the tumor, which was adequately detected by the proposed method.

14:30         4204.     Acute Vascular and Non-Vascular Enhanced MRI Measurements Made in C6 Tumour Xenografts Before and After MLN0518, a Potent PDGFRβ  Inhibitor, Treatment.

Daniel Philip Bradley1, Jennifer Terkelsen, Donna Cvet, Barbara Hibner, Kristine Burke, Matthew D. Silva

1Imaging Sciences, Millennium: The Takeda Oncology Company, Cambridge, MA, USA

In this study, single slice T1, T2, ADC and DCE-MRI were performed in established C6 glial s.c. xenograft tumours before and 72 hours after MLN0518 treatment (20mg/kg s.c. BID). Complimentary exvivo microCT was performed to explore vessel architecture. A significant decrease in iAU[Gd]C is reported after MLN0518 treatment compared to vehicle. Preliminary changes are observed in the vascular phenotype after MLN0518 treatment. No change in T2 or ADC was found. The present in vivo results support a haemodynamic change during acute dosing of MLN0518 in this preclinical model.

15:00         4205.     Longitudinal Study of 1H MRS of Lactate Upon Treatment in a Non-Hodgkin’s Lymphoma Patient

Seung -Cheol Lee1, Eric A. Mellon1, Harish Poptani1, Edward James Delikatny1, Jerry David Glickson1

1Dept of Radiology, University of Pennsylvania, Philadelphia, PA, USA

Previously we’ve shown in a human lymphoma xenograft model that in vivo MRS detected lactate is a very early marker of response to either CHOP or R-CHOP therapy. Last year we’ve presented clinical scanner version of the lactate detection sequence (Hadamard-SelMQC-CSI) in the phantom studies. This year we applied the clinical scanner version of the lactate sequence to monitoring early response to R-CHOP therapy in a non-Hodgkin’s lymphoma patient.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 70

13:30         4206.     Dynamic Contrast Enhancement (DCE) MRI of Parotid Glands After Radiotherapy

Kar-ho Francis Lee1, Ka-Wai Yeung1, Koon-Ming Kam2, Buig-Yu Ma2, Ann Dorothy King1, Kwok-Hung Yu2, Chen Wu Hu3, Anil Ahuja1

1Departmemt of Radiology and Organ Imaging, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China; 2Departmemt of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China; 3Shenzhen Fifth Hospital and Luo-hu District Hospital, Shenzhen, Guangdong, China

Radiation injury occurs in the parotid glands of patients being irradiated for head and neck cancer. Increased contrast enhancement in MRI of parotid glands after radiotherapy has been reported and so to improve the understanding of radiation injury we studied further these changes in contrast enhancement using dynamic contrast enhancement MRI (DCE-MRI).

14:00         4207.     Hierarchical Versus Voxel-Wise Models for DCE-MRI in a Head and Neck Study with Lapatinib

Brandon Whitcher1, Volker J. Schmid2, David Collins3, Matthew Orton3, Dow-Mu Koh3,4, Josep M. del Campo5, Kevin Harrington6, Iman A. El-Hariry7

1Clinical Imaging Centre, GlaxoSmithKline, London, UK; 2Institute of Biomedical Engineering, Imperial College, London, UK; 3CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey, UK; 4Department of Radiology, Royal Marsden Hospital, Sutton, Surrey, UK; 5Department of Medical Oncology, Vall d'Hebron Hospital, Barcelona, Spain; 6Targeted Therapy Team, Institute of Cancer Research, London, UK; 7Oncology Medicine Development Centre, GlaxoSmithKline, London, UK

We compare the results from a quantitative analysis of DCE-MRI data using summary statistics from a non-linear regression analysis, using both optimization and Bayesian methods, and the output from a Bayesian hierarchical model in a phase II study of lapatinib in patients with locally advanced squamous cell carcinoma of the head and neck.

14:30         4208.     Multiparametric Non Invasive MRS Evalutation of Cisplatin Treatment in Ovarian Cancer

Maria Elena Pisanu1, Rossella Canese1, Alessandro Ricci1, Massimo Giannini1, Luisa Paris1, Massimo Spada1, Carmela Rozera1, Albino Cesolini1, Filippo Belardelli1, Paola Alberti2, Delia Mezzanzanica2, Silvana Canevari2, Egidio Iorio1, Franca Podo1

1Istituto Superiore di Sanità, Roma, Italy; 2Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy

Purpose of this study was to investigate the effects induced by cisplatin on MRS profiles of the human ovarian cancer cell line SKOV3ip either cultured in vitro or implanted in immunodeficient mice.

15:00         4209.     Dynamic-Contrast Enhanced MRI and MR-Guided Biopsy in the Detection of Local Recurrence After Radiation Therapy for Prostate Cancer

Derya Yakar1, Thomas Hambrock, Henkjan Huisman, Tom Scheenen, Christina Hulsbergen-vandeKaa, Emile van Lin, Jelle Barentsz, Jurgen Fütterer

1Radiology, UMC St Radboud, Nijmegen, Gelderland, Netherlands

Currently used techniques in the detection of prostate cancer recurrence after radiotherapy are inadequate. We studied the potential of Dynamic-Contrast Enhanced (DCE) MRI in combination with MR guided biopsy of tumor suspicious regions (TSR) to improve detection of local prostate cancer recurrence following radiotherapy. 15 Patients with 3 consecutive rises in prostate specific antigen (PSA) level after radiotherapy underwent MRI at 3T. TSR were determined from T2-weighted MR images and DCE-MR images. An MR-guided biopsy was taken from these TSR. Prostate cancer was found in 13/15 patients. 22/29 TSR were positive for tumor on biopsy.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 70

13:30         4210.     Effects of Intensity Modulated Radiotherapy (IMRT) on Prostate Volume – Comparison of 39 Patients Before and After Radiotherapy

Christian M. Zechmann1, Khurram Aftab1, Patrik Zamecnik1, Frederik L. Giesel1, Christian Thieke2, Jurgen Fütterer3, Anette Kopp-Schneider4, Stefan Delorme5

1Radiology, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wuerttemberg, Germany; 2Radiotherapy, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wuerttemberg, Germany; 3Radiology, University Medical Centre Nijmegen, Nijmegen, Netherlands; 4Biostatistics, German Cancer Research Center (DKFZ),, Heidelberg, Baden-Wuerttemberg, Germany; 5Radiology, German Cancer Research Center (DKFZ),, Heidelberg, Baden-Wuerttemberg, Germany

The shrinking effect of androgen deprivation therapy (ADT) on prostate volume is a known finding but data on volume changes during radiotherapy is inconsistent. We examined patients with and without ADT undergoing intensity modulated radiotherapy (IMRT). Patients undergoing IMRT show definite prostate shrinkage in T2w MRI. The rate is slowed down after 6 months in both groups, whereas the volume reduction is significantly larger in patients without ADT. Nevertheless there is no adding effect of ADT+IMRT vs. IMRT alone.

14:00         4211.     Change in ADC Values in the Prostate During Radiotherapy.

Daniel Wilson1, Sarah Bacon1, Alastair McCabe1, Brendan Carey2

1Medical Physics, St James's Institute of Oncology, Leeds, West Yorkshire, UK; 2Radiology, St James's Institute of Oncology, Leeds, West Yorkshire, UK

The apparent diffusion coefficient (ADC) was measured in the prostate pre- and post-external beam radiotherapy in 17 patients`. There was a significant reduction in ADC post radiotherapy in both normal and malignant regions. Further measurements of ADC at other time points are needed to fully characterise the time course of any changes.

14:30         4212.     Assessment of Radiotherapy Treatment in Cervical Cancer Using Proton Magnetic Resonance Spectroscopy at 3 Tesla: A Pilot Study

Yao Ding1, Robert doug Sims1, Jaya Lea1, Paul Weatherall1, Ralph Mason1

1Radiology, UT southwestern medical center at dallas, dallas, tx, USA

The preliminary results of our pilot study indicate that pre-treatment choline level can be used as a marker for evaluating treatment response in patients with cervical cancer using external surface coil at 3 T.

15:00         4213.     3.0T MR Diffusion-Weighted Imaging in Monitoring Diffusion Changes in Lung Carcinoma After Chemoradiation

Qing Chang1, Ning Wu1, Han Ouyang1, Yao Huang1

1Department of Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China

To evaluate the clinical value of diffusion-weighted imaging (DWI) in monitoring response of lung carcinoma to chemoradiation using 3.0T MR scanner. The ADCs of lung cancers were markedly increased after chemoradiation.

 


 
Tumor Perfusion & Permeability
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 71

14:00         4214.     Delay and Dispersion Correction for Simultaneous Quantification of Perfusion and Permeability in the Prostate Using DCE-MRI with a Dual-Contrast Sequence

Lutz Lüdemann1, Tobias Franiel2, Matthias Taupitz2, Hagen Rehbein1, Dirk Beyersdorff2

1Department of Radiotherapy, CVK, Charité, Berlin, Germany; 2Department of Radiology, Charité, Berlin, Germany

Contrast enhancement of the prostate in dynamic MR imaging can be used to assess perfusion and permeability using a low-molecular-weight con-trast medium. The arterial input function is subject to delay and dispersion during its passage from the point of measurement to the tar-get voxel. The dispersion is inherently coupled to the delay. Whereas the delay can easily assessed the bolus dispersion is caused by two proc-esses, the dispersion during its passage from the point of measurement to the tissue and the dispersion by the tissue passage expressed by the mean transit time.

14:30         4215.     Evaluation of Slope-Based Hepatic Perfusion Index Quantification Methods Against Dual-Input Kinetic Model Based Approach

Keiko Miyazaki1, Matthew R. Orton1, Dow-Mu Koh1, V Lewington2, David Atkinson3, David J. Hawkes3, Martin O. Leach1, David J. Collins1

1Cancer Research UK Clinical Magnetic Resonance Research Group, The Institute of Cancer Research, Sutton, Surrey, UK; 2Department of Nuclear Medicine and PET, The Royal Marsden NHS Foundation Trust, Sutton, UK; 3Centre for Medical Image Computing, University College London, London, UK

The hepatic perfusion index can be quantified using slope-based methods which are simpler to compute and easier to implement in clinical settings compared with dual-input kinetic modelling methods. In this study, HPI was evaluated using two slope-based methods (the Miles method and a modified Blomley method). These were compared with parameters derived using a dual-input single compartment model with population-averaged input functions. It was found that the Miles method overestimates the HPI in the surrounding liver tissue whilst the modified Blomley method produces HPI values that are in good agreement with both the model-derived and previously published literature values.

15:00         4216.     The Effect of Image Registration on Pharmacokinetic Parameter Extraction Using 3D DCE-MRI

Andrew Melbourne1, Matthew Orton2, David Collins2, Dow-Mu Koh2, Martin Leach2, David Hawkes1, David Atkinson1

1University College London, London, UK; 2Institute of Cancer Research, London, UK

Residual patient motion between images in breath-hold DCE-MRI may compromise image. This work analyses results of a Progressive Principal Component Registration (PPCR) algorithm on six 3D DCE-MRI datasets. The datasets used here are analysed using a full pharmacokinetic analysis of the liver in order to extract pharmacokinetic parameters from each pixel. Inspecting the average change in the total model fit residual for all six datasets reveals an average decrease of –1.5±2.7% after direct fluid-based image registration and –15±4% after registration by PPCR. The PPCR algorithm has been shown to allow improved model fitting by reduction in the model-fit residuals.

15:30         4217.     Assessing the Effects of Water Exchange on Quantitative Dynamic Contrast Enhanced MRI (DCE-MRI) by Comparison with DCE-CT

Lauren Jean Bains1, Deirdre M. McGrath1, Josephine H. Naish1, Susan Cheung1, M B. Taylor2, J P. Logue2, Geoff J M Parker1, John C. Waterton1,3, David L. Buckley1

1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, UK; 2Christie Hospital, Manchester, UK; 3AstraZeneca, Alderley Park, Macclesfield, Cheshire, UK

Because contrast agent concentration is measured indirectly in MRI via its effect on the surrounding water molecules, the rate of water exchange between tissue compartments can affect quantitative parameters calculated using DCE-MRI data. Since DCE-CT is not affected by water exchange, a comparison was made between DCE-MRI and DCE-CT to assess the impact of water exchange on DCE-MRI data. Two limiting cases of water exchange were examined; at one limit, flow may be underestimated while at the other limit blood volume was overestimated. Preliminary attempts failed to estimate water exchange rates, suggesting the need for further water exchange sensitive data.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 71

13:30         4218.     Comparison of Blood Flow Measurements Using 2-Compartment Model and Deconvolution Based Analysis of T1-Weighted DCE MRI of Breast Tumors

Smitha Makkat1, Robert Luypaert1, Johan De Mey1, Steven Sourbron2

1Radiology/BEFY, Vrije Universiteit Brussel, Brussels, Belgium; 2Radiology, University Munich - Grosshadern Hospital, Munich, Germany

An accurate assessment of the Tumor Blood Flow can become crucial in deciding the best management for breast cancer patients. In this study, the aim is to compare the model-free blood flow values derived with deconvolution analysis against those derived with a 2-compartment uptake model. Model-free and model based tumor blood flow are well-correlated, but there is a systematic difference in the values obtained.

14:00         4219.     Quantitative MRI Assays of Angiogenesis with Microscopic Correlation in a Bevacizumab-Treated Human Breast Cancer Model

Hans-Juergen Raatschen1, Barbara Sennino2, Yanjun Fu3, David M. Shames3, Robert C. Brasch3

1Radiology, Charite - Campus Benjamin Franklin, Berlin, Germany; 2Cardiovascular Research Institute, Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA; 3Radiology, University of California San Francisco, San Francisco, CA, USA

The purpose of our study was to compare and correlate a macromolecular contrast-(MMCM)-enhanced MRI-technique for measuring tumor vascular richness with perfusion-dependent fluorescent microscopy in an angiogenically inhibited human breast cancer model. MRI estimates of fractional plasma volume, fPV, were in good proportional agreement with lectin area density, the microscopic measure of vascular richness (r2=0.74, p<0.001). Thus, fPV can be estimated reliably in cancers by non-invasive MMCM-enhanced dynamic MRI.

14:30         4220.     DCE and DWI in Evaluating Grades of Gliomas

Bob Lei Hou1, Li Meng2, Sasan Karimi3, Weihua Liao2, XiaoYi Wang2

1Medical Physics and Radiology , MSKCC, New York City, NY, USA; 2Radiology, Central South University, Changsha, Human, China; 3Radiology, MSKCC, New York City, NY, USA

MRI perfusion (DCE) has been applied in evaluating grades of gliomas. We hypothesized that micro vascularity changes related to the tumor grade can be reliably detected with DCE and that vessel permeability (i.e., leakage, ~~Ktrans) of the brain tumors increase with the grade. In this study, we used DCE perfusion and diffusion weighted imaging (DWI) techniques on a group of patients with variable grades of gliomas. Our aims were to evaluate relationships between the tumor grade and perfusion and diffusion parameters and to seek out one of the most sensitive and specific parameters for demonstrating the changes in the tumor vascularity, capillary integrity and cell density with the tumor grade. Our results from DCE and DWI suggest Ktrans (~~permeability) is the most sensitive and specific parameter for separating the low from high grade gliomas, and the threshold of Ktrans values for distinguishing the low from high grade gliomas was found as 0.8 (sensitivity= 92 & specificity=90).

15:00         4221.     Systematic DCE-MRI Parameter Errors Caused by Disproportionate Transverse Relaxation (T2*) Quenching of Tissue Compartmental Water Proton Signals

Xin Li1, Ryan A. Priest2, Faisal Siddiqui3, Tomasz M. Beer4,5, Mark G. Garzotto6,7, William J. Woodward1, William D. Rooney1, Charles S. Springer, Jr. 1

1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, USA; 2Departments of Radiology, Oregon Health & Science University, Portland, OR, USA; 3School of Medicine, Oregon Health & Science University, Portland, OR, USA; 4Departments of Hematology/Oncology, and Urology, Oregon Health & Science University, Portland, OR, USA; 5Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA; 6Portland VA Medical Center, Portland, OR, USA; 7Department of Urology, Oregon Health & Science University, Portland, OR, USA

Dynamic-contrast-enhanced (DCE)-MRI pharmacokinetic modeling usually ignores potential water proton signal reduction due to transverse relaxation effects. Using prostate DCE-MRI data, we investigate a potential transverse relaxation effect on DCE-MRI model parameter values, by using a water exchange (“shutter-speed”) model along with a simplified factor to account for putative transverse relaxation signal quenching.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 71

13:30         4222.     Hepatic Perfusion Quantification Using a Dual-Input Kinetic Model with a Novel Portal Venous Estimation Method: Evaluation Against Other Model- And Slope-Based Perfusion Quantification Approaches

Keiko Miyazaki1, Matthew R. Orton1, Dow-Mu Koh1, V Lewington2, David Atkinson3, David J. Hawkes3, Martin O. Leach1, David J. Collins1

1Cancer Research UK Clinical Magnetic Resonance Research Group, The Institute of Cancer Research, Sutton, Surrey, UK; 2Department of Nuclear Medicine and PET, The Royal Marsden NHS Foundation Trust, Sutton, UK; 3Centre for Medical Image Computing, University College London, London, UK

Hepatic perfusion quantification can be performed via kinetic modelling of dynamic contrast enhanced (DCE-) MR data using a dual-input single compartment model. A methodology which estimates portal venous contributions directly from liver tissue DCE-MR data, has been developed and submitted to this conference. In this study, we have quantified hepatic perfusion in clinical patient data using the novel model-based approach. The perfusion metrics obtained compared favourably with those quantified using a dual-input single compartment model with population-averaged arterial and portal input functions and a dual slope, modified Blomley method.

14:00         4223.     Contrast Enhanced Image Registration Using Kullbach-Leibler Assisted Image Matching and Patching (KLAMP)

Andrew Melbourne1, David Collins2, Martin Leach2, Dow-Mu Koh1, David Hawkes1, David Atkinson1

1University College London, London, UK; 2Institute of Cancer Research, London, UK

Contrast Enhanced MRI data often consists of frames with large changes in pixel intensity values. Image alignment algorithms may incorrectly shrink enhancing features. If there are features in the joint image histogram used for image registration between pre and post enhancement images that are due to enhancement processes, we seek to minimise those changes by comparison with a joint image histogram containing only motion artefacts. The post enhancement image is masked so that enhancing pixels do not impact on the formation of image force gradients such as those used in fluid registration. Suppression of force gradients formed by enhancing features reduces the risk of mis-registration in these.

14:30         4224.     Applications of Dynamic Contrst-Enhanced MRI in Assessment of Spinal Bone Marrow

Kyung K. Peck1, Gregg Slater2, Xiuyuan Wang3, SeungEun Kim4, Josh Yamada5, Mark Bilsky6, Eric Lis2, Sasan Karimi2

1Radiology and Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, USA; 2Neuroradiology, Memorial Sloan-Kettering Cancer Center, New York, USA; 3The City Unversity of New York, New York, USA; 4Stony Brook University, New York, USA; 5Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, USA; 6Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, USA

Application of DCE MRI to the study of bone marrow between ages, sex subgroups, and among spinal levels has already shown variations in bone marrow time intensity curves. Since these differences influence the appearance of the marrow and its dynamic profile we sought to investigate the utility of DCE MRI. We investigated the bone marrow of the spine using a contrast enhanced dynamic perfusion MRI, and the parameter measured was the bolus wash-in slopes. Significant Statistical differences in the enhancement percentage signal change were found between hypervascular and hypovascular tumor groups. A trend showing statistical differences was found using enhancement slope measurement. The signal in normal marrow as compared to tumors showed no significant enhancement patterns.

15:00         4225.     Enhancing Fraction Predicts Recurrence-Free Survival in Patients with Carcinoma of the Cervix Treated with Radiotherapy

Stephanie B. Donaldson1,2, James P.B. O'Connor2, Catharine M.L. West3, Bernadette M. Carrington4, Susan E. Davidson5, Andrew P. Jones1, David L. Buckley2

1North Western Medical Physics, Christie Hospital NHS Foundation Trust, Manchester, UK; 2Imaging Science and Biomedical Engineering, University of Manchester, Manchester, UK; 3Academic Department of Radiation Oncology, University of Manchester, Manchester, UK; 4Department of Radiology, Christie Hospital NHS Foundation Trust, Manchester, UK; 5Department of Clinical Oncology, Christie Hospital NHS Foundation Trust, Manchester, UK

Patient survival in cervical cancer varies considerably. There is a need to predict which patients are unlikely to respond to therapy. DCE-MRI studies were performed in 46 patients pre-external beam radiotherapy (EBRT) and in 10 patients post-EBRT. The enhancing fraction of each tumour (EF = enhancing voxels / total tumour voxels) was calculated at 25, 50, 75 and 100s post-contrast. Patients with low EF had significantly better recurrence-free survival than those with high EF and EF increased post-EBRT. High EF may indicate more aggressive / angiogenic tumours and is a simple radiological biomarker of prognosis in patients with cervix tumours.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 71

13:30         4226.     Galbumin, a New Blood Pool Agent, Extravasates from Tumour Vasculature

Firas Moosvi1,2, Jennifer Baker3, Stefan A. Reinsberg4

1Physics, University of British Columbia, Richmond, BC, Canada; 2Medical Biophysics, BC Cancer Research Center, Vancouver, BC, Canada; 3Medical Biophysics, BC Cancer Research Center, Vancouver, British Columbia, Canada; 4Physics, University of British Columbia, Vancouver, BC, Canada

A macromolecular contrast agent (Galbumin) is shown to slowly extravasate in "leaky" tumour vasculature. We use fluorescent microscopy and dynamic contrast enhanced MRI to prove this.

14:00         4227.     Vessel Size Index and Blood Volume Imaging in Pancreatic Cancer Xenograft Model Using Ferumoxide

Andrew C.H. Yung1, Jenny C.H. Tso1, Jennifer Flexman1, Sylvia Ng1,2, Donald Yapp1,2, Piotr Kozlowski1

1University of British Columbia, Vancouver, BC, Canada; 2British Columbia Cancer Research Centre

The use of ferumoxide is investigated for use in the blood volume fraction (BV) and vessel size index (VSI) measurements of a xenograft mouse model of pancreatic cancer. The ferumoxide susceptibility contrast remains stable for at least 1.5 hours after injection. Spectroscopy measurements produce a susceptibility value of 1.37 ppm for ferumoxide in blood. BV was well correlated with a histology measure of perfused tumour vessels, and VSI showed good correlation with BV. We show that ferumoxide can be successfully used in BV and VSI measurements.

14:30         4228.     Reproducibility and Cross-Validation of DCE-MRI and DCE-CT Perfusion Parameters in a Rat Tumor Model

Chaan S. Ng1, Jim A. Bankson2, Vikas Kundra1, John C. Waterton3, Ed F. Jackson2

1Radiology, MD Anderson Cancer Center, Houston, TX, USA; 2Imaging Physics, MD Anderson Cancer Center, Houston, TX, USA; 3Astra-Zeneca, Alderley Park, Macclesfield, Cheshire, UK

The reproducibility of DCE-MRI parameters, as assessed by CV%, is in the range 13.4-16.6%, and appears better than for DCE-CT parameters (range 16.5-25.5%). The latter however may allow discrimination of perfusion and permeability, which the composite DCE-MRI parameter, Ktrans, does not. This may be of importance in future antiangiogenic targets.

15:00         4229.     Measuring Non-Invasively Tumor Perfusion and Diffusion as a Function of Tumor Progression Using Proton Magnetic Resonance Imaging (1H MRI)

Asif Rizwan1,2, Hyung JoonCho1, Ellen Ackerstaff1, Jason Koutcher1

1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 2Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA

Diffusion-weighted 1H MRI and dynamic contrast-enhanced 1H MRI have been highly developed to provide quantitative measurements of tissue properties that are greatly relevant to evaluating tumor progression and treatment response. Here, we hypothesize that the tumor microenvironment can be evaluated non-invasively by measuring the changes in tumor water diffusion and tumor perfusion. To prove this hypothesis, we mapped the apparent diffusion coefficient of water in the tumor, mapped the tumor according to the received concentration of the contrast agent Gd-DTPA and relate viable and non-viable tumor regions as obtained from ex vivo histology to the in vivo data.

 


 
Breast Cancer Clinical Studies
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 72

14:00         4230.     Improved Characterization of Breast Lesions with Relative ADC Accounting for Tissue Composition Variation

Jie Huang1, Lori Hoisington1, Tobias Hahn1,2, Anna Babayan3, Kevin Berger1

1Department of Radiology, Michigan State University, East Lansing, MI, USA; 2Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA; 3College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA

DWI has been used recently to investigate the potential application of ADC in the characterization of breast lesions. Studies found that the ADC of malignant tumors was significantly smaller than that of benign lesions, reflecting increased cellularity of the malignant tumors. However, breast tissue composition varies substantially from person to person and could mask the effect of cellularity changes on ADC. In this study we investigated the correlation between the ADC of breast lesions and the ADC of the immediate surrounding tissues and then examined the effect of tissue composition variation on the characterization of the breast lesions.

14:30         4231.     The Role of Diffusion Weighted Imaging (DWI) and Volumetric Measurement in the Early Assessment of Tumor Response in Patients with Locally Advanced Breast Cancer (LABC) Undergoing Primary Chemotherapy (PCT).

Laura Martincich1, Ilaria Bertotto1, Filippo Montemurro2, Lisa Cellini1, Ivana Sarotto3, Daniele Regge1

1Diagnostic Unit, Institute for Cancer Research and Treatment, Candiolo, Turin, Italy; 2Medical Oncology Unit, Institute for Cancer Research and Treatment, Candiolo, Turin, Italy; 3Pathology Unit, Institute for Cancer Research and Treatment, Candiolo, Turin, Italy

The aim of the study was to evaluate if DWI and DCE-MRI may early define tumor response in 17 patients with Locally Advanced Breast Cancer (LABC) undergoing PCT.

15:00         4232.     Determination of the Optimum B-Value for Diffusion Weighted Image of the Breast

Reiko Woodhams1,2, Saadallah Ramadan2, Mayumi Satou1, Hirofumi Hata1, Satoko Kakita1, Naoko Yoshimura3, Keiichi Iwabuchi4, Masanori Ozaki1, Shinichi Kan1

1Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan; 2Radiology, Brigham and Women's Hospital, Boston, MA, USA; 3Department of Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan; 4Department of pathology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan

This study evaluated optimal b-values for breast DWI.110 subjects (18 benign 92 malignant) were analyzed by comparing ADC values, signal to noise ratio (SNR) and tumor-normal contrast noise ratio (CNR) between b=1000 and 1500s/mm2in benignity and malignancy respectively. A b-value of1500s/mm2may be more appropriate for discrimination of histologic types because of increase of SNR and CNR with b-500s/mm2 from those with b-1000 s/mm2 in malignancy with smaller SNR and CNR. Inversely, b=1000s/mm2 will be more appropriate for screening purpose because of better SNR and CNR for benign as well as malignancy compared to those withb=1500s/mm2.

15:30         4233.     Microperfusion-Induced Elevation of ADC Is Suppressed After Contrast in Breast Carcinoma

Sachiko Yuen1, Mariko Goto1, Kei Yamada1, Akiko Takahata1, Kaori Nishida1, Tsunehiko Nishimura1

1Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan

Post-contrast ADC exhibited a significant lower value (-23%, p=0.01) than pre-contrast ADC in breast carcinoma, which is thought to reflect the suppression of the microperfusion-induced effect on DWI. When early post-contrast images were used as a surrogate marker of tumor aggressiveness, we found a significant inverse correlation with the post-contrast ADC (&#61543; = -0.57, p=0.02). Post-contrast ADC may be a better indicator to reflect the aggressiveness of tumors.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 72

13:30         4234.     Measuring Water T2 and Water:fat Signal Ratios with MR Spectroscopy (TEA-PRESS) and Chemical Shift Imaging (IDEAL): Preliminary Results in Phantoms and Breast Cancer Chemotherapy Patients

David John Manton1, Gary Paul Liney1, Peter Gibbs1, Martin Lowry1, Martin Darren Pickles1, Lindsay W. Turnbull1

1YCR Centre for MR Investigations, Hull, East Yorkshire, UK

Water and fat T2s, and water content (water signal / sum of water and fat signals) were measured in nine breast cancer patients prior to neoadjuvant chemotherapy using MR spectroscopy (TEA-PRESS) and chemical shift MRI (IDEAL). IDEAL, with greater spatial resolution, detected legion heterogeneity, but its T2 values were systematically higher than the TEA-PRESS values by a factor of 1.69. IDEAL water content values appeared to be overestimated for low values (<60%) and underestimated for higher values (>80%). Investigations are underway to determine the underlying reasons for these errors which should permit a thorough, theoretical correction of the data.

14:00         4235.     Quantitative Proton Single-Voxel MR Spectroscopy in Malignant Breast Tumors at 3T: A Preliminary Study

Hyeon-Man Baek1, Hon J. Yu2, Shadfar Bahri2, Jeon-Hor Chen2, Orhan Nalcioglu2, Min-Ying Su2

1Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA; 2Center for Function Onco-Imaging, University of California-Irvine, Irvine, CA, USA

In vivo proton MR spectroscopy (1H-MRS) has been shown to improve cancer diagnosis based on elevated choline-containing compounds (tCho). In this study, in vivo quantification of tCho signal from the 12 malignant breast tumors at 3T was carried out with the AMARES method using a prior knowledge. After T1 and T2 relaxation times were corrected, the tCho levels in this work had a range of 0.19 – 3.05 mmol/kg and that is consistent with previously published values in the literature. 2 (17%) of 12 lesions showed that the CRLB exceeded the estimate. Therefore, we conclude that the internal method using the fully relaxed water as a reference could be used for quantifying tCho metabolite accurately in breast cancer patients using a 3T scanner.

14:30         4236.     Quantification of Absolute Concentration of Choline for Differentiation of Malignant, Benign and Normal Breast Tissues by In-Vivo Proton MR Spectroscopy.

Rani Gupta Sah1, Uma Sharma1, Rajinder Parshad2, Naranamangalam R. Jagannathan1

1Department of NMR and MRI Facility, All India Institute of Medcial Sciences, New Delhi, Delhi, India; 2Department of Sugical Disciplines, All India Institute of Medcial Sciences, New Delhi, Delhi, India

Absolute concentration of tCho was determined in breast tissue of 87 women including 52 patients with infiltrating ductal carcinoma, 15 benign and 20 normal volunteers using in-vivo proton MRS at 1.5 T. tCho signal was observed in all malignant and in 13/15 benign lesions and 8/20 normal volunteers. Concentration of tCho was 4.04 ± 2.08 mmol/kg in malignant tumor which was significantly higher compared to benign (1.37 ± 0.8 mmol/kg) and normal tissues (0.40 ± 0.24 mmol/kg) suggesting that quantitative measurements provide unambiguous diagnosis of breast lesions. No significant difference was observed in tCho concentration between volunteers and benign lesions.

15:00         4237.     Statistical Analysis of Two Dimensional MR Spectroscopy Combined with Dynamic Contrast Enhanced MRI in Breast Cancer Detection

Xiaoyu Liu1, Scott Lipnick1, James Sayre1, Nanette Debruhl1, Aparna Singhal1, Albert Thomas1

1Radiology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA, USA

DCE MRI combined with 2D L-COSY can increase breast cancer detection specificity; 2D L-COSY can detect Choline which can be used as a biomarker to differentiate between malignant and benign tumors. 2D COSY of breast tissues showed several other metabolite and lipid ratios are significantly different between malignant tumor and benign tumor. A major goal of this work was to investigate the feasibility of using statistical analysis of 2D L-COSY combined with DCE MRI to classify malignant and benign breast tumors.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 72

13:30         4238.     Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Breast at 3.0 Tesla: Combination of High Temporal- And Spatial Resolution - A New Approach

Guenther Grabner1, Katja Pinker2, Stephan Gruber3, Wolfgang Bogner1, Thomas Helbich2, Siegfried Trattnig1,4

1MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 2Department of Radiology, Medical University of Vienna, Vienna , Austria; 3MR Centre of Excellence, Medical University of Vienna, Vienna , Austria; 4Department of Radiology, Medical University of Vienna, Vienna, Austria

This work is focused on automatic classification of lesions as malignant or benign and on the bottleneck of DCE-MRI, the trade-off between spatial and temporal resolution. The DCE-MRI approach presented here combines high spatial and temporal resolution by splitting the DCE-MRI imaging protocol into three parts (high temporal resolution measurements; a high spatial resolution measurement at contrast maximum followed by high temporal resolution measurements). Enhancement curves obtained from 3D manually drawn regions of interest were fitted using a modified asymmetric logistic model. Model and secondary parameters were successfully classified as malignant or benign using k-means.

14:00         4239.     Pharmacokinetic Parametric Mapping and Pixel Histogram Analysis for Benign and Malignant Breast Lesion Discrimination: A Preliminary Shutter-Speed DCE-MRI Study

Ian Tagge1, Yiyi Chen1, Xin Li1, Elizabeth Morris2, Alina Tudorica1, Charles Springer1, Wei Huang1

1Oregon Health & Science University, Portland, OR, USA; 2Memorial Sloan Kettering Cancer Center, New York, NY, USA

Region-of-interest (ROI) biomarkers extracted from shutter-speed model (SSM) analyses of DCE-MRI time-course data have high specificity for breast cancer diagnosis. By pharmacokinetic parametric mapping and histogram analyses, this preliminary study of 16 patients with suspicious breast lesions shows that pixel-by-pixel analyses of pharmacokinetic parameters eliminate partial volume averaging effects of ROI analyses and further improve diagnostic accuracy.

14:30         4240.     A High Specificity Biomarker for Breast Cancer Diagnosis: Shutter-Speed DCE-MRI Discrimination Among Seventy Seven Suspicious Lesions

Wei Huang1, Xin Li1, Alina Tudorica1, Elizabeth Morris2, Yiyi Chen1, Ian Tagge1, Sunitha Thakur2, Maayan Korenblit2, Ya Wang2, Zhigang Zhang2, Jason Koutcher2, Charles Springer1

1Oregon Health & Science University, Portland, OR, USA; 2Memorial Sloan Kettering Cancer Center, New York, NY, USA

In a DCE-MRI study of 77 suspicious breast lesions, it is demonstrated that, for the purpose of benign and malignant lesion discrimination, the region-of-interest (ROI) pharmacokinetic biomarkers extracted from the shutter-speed model (SSM) analysis of the time-course data perform significantly better than those derived from the standard model (SM) analysis or conventional clinical MRI interpretations. The Ktrans difference, δKtrans (SSM Ktrans – SM Ktrans), represents the strongest binary classifier with 88% specificity for 100% sensitivity. Parametric maps may allow even greater specificity.

15:00         4241.     Kinetics and Morphology of Biopsy-Proven DCIS on Preoperative MRI:  Can We Predict Occult Invasive Disease?

Dorota Jakubowski Wisner1, Belinda Chang1, Hilda Tso1, Christopher Flowers1, Bonnie N. Joe1, Juan Lessing2, Jessica Gibbs1, Kaoru Itakura3, Shelley Hwang3, Nola Hylton1

1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA; 2School of Medicine, University of California, San Francisco, San Francisco, CA, USA; 3Surgery, University of California, San Francisco, San Francisco, CA, USA

In this study we evaluate the ability of breast MRI to predict occult invasion in patients initially diagnosed with pure ductal carcinoma in situ (DCIS). A comprehensive search of our institution’s archives identified 51 preoperative MRI scans obtained after a core-biopsy diagnosis of DCIS. A radiologist blinded to surgical histopathology categorized these lesions and estimated likelihood of occult invasion. Results demonstrate 92% sensitivity, 58% specificity and 96% negative predictive value for occult invasion. These findings suggest that a negative preoperative MRI may assist risk stratification, affecting such decisions as surgical management and need for sentinel lymph node biopsy.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 72

13:30         4242.     Feasibility of MRI-Guided Large Core-Needle Biopsy of Suspiscious Breast Lesions at 3T

Nicky HGM Peters1, Carla Meeuwis2, Chris JG Bakker1, Willem PThM Mali1, Arancha M. Fernandez-Gallardo1, Richard van Hillegersberg3, Marguerite E.I. Schipper4, Maurice A.A.J. van den Bosch1

1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiology, Alysis Zorggroep, Rijnstate Hospital, Arnhem, Netherlands; 3Surgical Oncology, University Medical Center Utrecht, Utrecht, Netherlands; 4Pathology, University Medical Center Utrecht, Utrecht, Netherlands

MRI-guided biopsy at 3T is a safe and effective method for breast biopsy in lesions that are occult on mammography and ultrasound. The size of the needle artefact does not hamper the biopsy procedure. Follow-up MRI at 6 months after the biopsy should be performed in case of a benign biopsy result.

14:00         4243.     3T Breast MRI Using Dixon Technique

Basak Dogan1, Jingfei Ma2, Ken Hwang2, Wei Tse Yang1

1Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA; 2Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA

We assessed a single pass gradient echo two-point Dixon sequence and a gradient echo sequence with spectral fat suppression in their performance at 3 Tesla for bilateral contrast-enhanced breast imaging. In eight patients evaluated by two breast imaging radiologists, improved fat suppression was achieved with the Dixon technique. Dixon technique was less sensitive to cardiac motion artifacts and improved the visualization of posterior structures. Margins and internal enhancement characteristics were better assessed in 28% of lesions. Our preliminary findings suggest that the Dixon technique may provide improved depiction of posterior structures and better anatomical definition of small lesions.

14:30         4244.     Characterization of Breast Tumors with a Model-Dependent Analysis of Bolus-Tracking MRI

Smitha Makkat1, Robert Luypaert1, Steven Sourbron2, Tadeusz Stadnik1, Johan De Mey1

1Radiology/BEFY, Vrije Universiteit Brussel, Brussels, Belgium; 2Radiology, University Munich - Grosshadern Hospital, Munich, Germany

We investigate whether a 2 compartment uptake model accurately describes high temporal resolution kinetics in breast pathology and also evaluate the resulting measured parameters in terms of tumor characterization in a small cohort of patients. We conclude that inclusion of the permeability parameter does not improve the differentiation potential in breast tumors. Malignant tumors with identical histopathology can exhibit different perfusion and permeability parameters, which points to the fact that DCE MRI can provide additional information that is not there in the histopathology.

15:00         4245.     Accurately Differentiating Benign from Malignant Contrast-Enhancing Breast Lesions Using an Automated Method of Quantitative Washout Kinetics and Fractional Lesion Volume Analysis

Jie Huang1, Tobias Hahn1,2, Lori Hoisington1, Kevin Berger1

1Department of Radiology, Michigan State University, East Lansing, MI, USA; 2Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA

Dynamic contrast-enhancing breast MRI has been shown to be very sensitive in cancer detection. Most malignant tumors demonstrate a rapid initial enhancement followed by a wash-out (WO) or plateau curve in the post-contrast signal intensity time courses, whereas most benign lesions exhibit a slow persistent enhancement. The WO curve mainly reflects the hypervascularity associated with tumor angiogenesis, and the total volume of the WO voxels may account for the degree of the hypervascularity. Benign proliferative breast diseases can also produce the WO curve, yielding an overlap between benign and malignant lesions and making them hardly distinguishable. Nevertheless, the WO volume fraction for benign proliferation might be relatively small in comparison to that for tumor angiogenesis, considering that an aggressive cancer cell growth is most likely accompanied by relatively larger angiogenesis. Thus, measuring the WO volume fraction may help in differentiating benign from malignant contrast-enhancing lesions.

 


 
Prostate Cancer
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 73

14:00         4246.     USPIO Enhanced Diffusion MRI Increases the Diagnostic Confidence for Detection of Pelvic Lymph Node Metastases in Patients with Bladder or Prostate Cancer

Maria Triantafyllou1, Johannes M. Froehlich2, Peter Vermathen3, Tobias Binser3, Frederic Birkhaeuser4, Achim Fleischmann5, Urs E. Studer4, Harriet C. Thoeny6

1Department of Diagnostic,  Interventional and Pediatric Radiology, Inselspital Bern, Bern, Switzerland; 2Guerbet, Switzerland; 3Department of Clinical Research, Inselspital, Bern, Switzerland; 4Department of Urology, Inselspital, Bern, Switzerland; 5Department of Pathology, Inselpital, Bern, Switzerland; 6Department of Diagnostic,  Interventional and Pediatric Radiology, Inselspital, Bern, Switzerland

 

14:30         4247.     Evaluating Prognostic Biomarkers of Prostate Cancer Behaviour: Use of Magnetization Transfer and Diffusion Weighted Contrast

Sophie Riches1, Vonnie A. Morgan1, David J. Collins1, Sharon Giles1, Nandita M. deSouza1

1CRUK Clinical Magnetic Resonance Group, Institute of Cancer Research & Royal Marsden NHS Trust, Sutton, Surrey, UK

Investigating the correlation of apparent diffusion coefficients (ADCs and magnetization transfer ratios (MTRs) may offer greater understanding of underlying tissue structure in prostatic tumors. This study determined the T2 values, ADCs and MTRs and the correlation between them in normal regions of the prostate and prostate tumors. A positive correlation between T2 and ADC, and a negative correlation between MTR and both T2 and ADC suggests that MTR imaging in the prostate warrants investigation with ADC as a prognostic biomarker.

15:00         4248.     Significantly Better Local Prostate Cancer Staging Performance with T2-Weighted 3T Endorectal Coil MR Imaging Compared with Real-Time Gray-Scale Tissue Harmonic Imaging TRUS

Stijn Wilhelmus Heijmink1, Tom W. Scheenen1, Thomas Hambrock1, Christina A. Hulsbergen-van de Kaa2, J A. Witjes3, Jelle O. Barentsz1

1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands; 2Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands; 3Urology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands

Thirty-five patients with clinically localized prostate cancer both underwent preoperative 3T T2-weighted endorectal coil MR imaging and real-time gray-scale tissue harmonic imaging transrectal ultrasound. Two readers independently scored all data sets. 3T ERC MR imaging achieved a significantly higher local prostate cancer staging performance compared with transrectal ultrasound. Also, for the most experience reader, sensitivity was significantly higher.

15:30         4249.     Evaluation of the Prostate After Treatment with High-Intensity Focussed Ultrasound (HIFU) Therapy Using Whole Prostate Diffusion Weighted Imaging (DWI) Analysis

Alex Chapman1, Nina Tunariu1, Veronica Morgan2, Nandita Desouza1

1Institute of Cancer Research, Sutton, Surrey, UK; 2Royal Marsden Hospital, Sutton, Surrey, UK

High intensity focussed ultrasound (HIFU) is increasingly being used to treat locally recurrent prostate cancer that has failed primary treatment. Nine patients were studied using a 1.5T Intera MR scanner with an endorectal receiver coil, before, after 6 weeks and after 6 months of HIFU treatment. Standard and diffusion-weighted images were acquired. ADCs and volumes for the whole gland were obtained for all time points. The results are suggesting that ADC at 6 weeks is an indicator of subsequent reduction in PSA. Earlier time points for measuring ADC may prove useful in predicting subsequent outcome and warrant further investigation.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 73

13:30         4250.     Monitoring Prostate Cancer Progression with Diffusion Weighted Imaging: Utility of Fast and Slow Diffusion Components of the Apparent Diffusion Coefficient.

Veronica Anna Morgan1, Sophie F. Riches2, Sharon Giles1, Nicholas Van As3,4, Chris Parker3,4, Nandita M. deSouza2

1Clinical Magnetic Resonance Group, Royal Marsden NHS Trust, Sutton, Surrey, UK; 2Clinical Magnetic Resonance Group, Institute of Cancer Research, Sutton, Surrey, UK; 3Academic Urology Unit, Royal Marsden NHS Trust, Sutton, Surrey, UK; 4Academic Urology Unit, Institute of Cancer Research, Sutton, Surrey, UK

Variability in fast and slow components of apparent diffusion coefficient (ADC) over whole prostate (WP) and tumor with time was investigated in patients on active surveillance. 32 patients studied at baseline and at a mean of 23months showed a significant reduction at TP2 compared to TP1 in tumor ADCoverall (5.2%; p=0.03) and ADCfast (4.3%; p=0.03) but not in ADCslow nor in any ADC components of WP. Those that progressed to radical treatment were primarily responsible for this effect and also demonstrated changes for WP in ADCoverall and ADCfast. For those that progressed on histology ADCoverall and ADCfast were significantly reduced compared to those that remained histologically stable. Changes in ADCfast over a 1-3yr time period show potential for monitoring disease progression in prostate cancer patients managed by active surveillance.

14:00         4251.     Shape-Based Interpolation of MRI Volumes in TRUS/Fusion Based Biopsy

xin chen1, Ramkrishnan Narayanan, John Kurhanewicz2, katsuto shinohara, David Crawford3, Anne Simoneau4, Jasjit S. Suri

1Eigen Inc., Grassvalley, CA, USA; 2University of California, San Francisco, USA; 3University of Colorado, Denver, Denver; 4University of California, Irvine

This project is to develop a fast shape-based inter-slice interpolation scheme to reduce the partial volume effect of large slice thickness while keeping less interpolation-induced blur, artifact and noise so that the subsequent segmentation, reconstruction and registration can be done with higher accuracy during TRUS/MRI fusion guided biopsy in ei-Nav/ArtermisTM . For real-time application, the GPU-based multithread (NVIDIA CUDA) programming was applied to reduce the elapsed time of this processing from hours to seconds.

14:30         4252.     Identification and Analysis of Metabolic Biomarkers for Predicting Prostate Cancer Grades Using 1H HR-MAS Spectroscopy of Biopsy Tissues

Vickie Zhang1,2, Maria Grinde3,4, Laura Tabatabai5, Jeff Simko5, Mark Albers1, Daniel Vigneron1, John Kurhanewicz1

1Radiology, University of California, San Francisco, San Francisco, CA, USA; 2Joint Bioengineering Program, University of California, Berkeley/San Francisco, San Francisco, CA, USA; 3Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 4St.Olav University Hospital, Trondheim, CA, Norway; 5Pathology, University of California, San Francisco, San Francisco, CA, USA

This study used quantitative 1-D 1H HR-MAS spectroscopy of snap frozen prostate biopsies to investigate the metabolic profiles of high (Gleason score &#8804; 3+3) versus low pathologic grade (Gleason score &#8805; 3+4) prostate cancer. Significantly higher concentrations of GPC, free choline, PE, alanine and glutamine were observed in high-grade versus low-grade prostate cancer. The concentration of lactate was also found to be higher in high-grade prostate cancer but this was not significant. By combining these metabolic changes, it may be possible to metabolically discriminate indolent from aggressive prostate cancer.

15:00         4253.     Asymmetry of Obturator Muscle Perfusion During Prostate MRI: Implications for the Reliability of Pharmacokinetic Analysis

Y Pang1,2, B Turkbey2, M Bernardo2,3, D Thomasson4, P Choyke2

1Philips Healthcare, Cleveland, OH, USA; 2Molecular Imaging Program, National Cancer Institute, Bethesda, MD, USA; 3SAIC-Frederick, Frederick, MD, USA; 4Clinical Center, National Institutes of Health, Bethesda, MD, USA

In quantitative analysis of prostate DCE-MRI data, accurate measurement of an AIF can be compromised by some artifacts. Recently, a reference region model has been proposed, where an AIF-substitute is derived from reference tissues with known kinetic parameters. This new approach has the potential to derive a reliable “AIF” from muscles near the prostate; however, the pharmacokinetic characteristics of enhancement within these muscles is not available in the setting of prostate cancer. In this study, we have measured the kinetic parameters of the obturator muscles for 12 patients and found intra- and inter-subject variations in their pharmacokinetics.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 73

13:30         4254.     Accuracy of MRI/3D-MRSI Based TRUS-Biopsy in Peripheral Zone (PZ) and Transition Zone (TZ) of Prostate Gland in Patients Suspected for Cancer with Prior Negative Biopsy

Claudia Testa1, Raffaele Lodi1, Caterina Tonon1, Riccardo Schiavina1, Giuseppe Martorana1, Alessandro Franceschelli1, Antonietta Derrico1, Romeo Canini1, Bruno Barbiroli1

1University of Bologna, Bologna, Italy

Transrectal ultrasound biopsy (TRUS-biopsy) was performed on regions with abnormal MRI and/or 3D-MRSI for both transition (TZ) and peripheral (PZ) zones in patients suspected for prostate cancer with prior negative biopsy. Successively the relationship between 3D-MRSI and histopathological findings was analyzed. Detection rate of cancer was 40.7%; accuracy of the combination of 3D-MRSI and MRI was 0.768 for PZ and 0.822 for TZ. Flogosis remains the main cause of 3D-MRSI false positive findings (28.8%) while benign prostatic hyperplasia and post inflammatory atrophy resulted substantially negative for 3D-MRSI (2.7% and 5.1% false positive findings respectively).

14:00         4255.     High-Resolution Diffusion-Weighted Imaging for the Diagnosis of Prostate Cancer

Carolin Reischauer1, Bertram Jakob Wilm1, Johannes M. Fröhlich2, Peter Boesiger1, Klaus U. Wentz1

1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland; 2Guerbet AG, Scientific Affairs, Zurich, Switzerland

Several studies have demonstrated the benefit of diffusion parameters as markers for prostate cancer imaging. Most of these studies have applied single-shot spin-echo EPI due to its high SNR-efficiency and its insensitivity to motion artifacts. The thereby achievable resolution is limited by susceptibility-related artifacts and T2*-blurring. The present work shows that a spatially reduced FOV can achieve submilimeter in-plane resolution which enables improved evaluation of diffusion parameters in localized structures of the prostate.The method is tested in a clinical study with patients suspected to suffer from prostate cancer and the findings are compared with a control group and with histopathology.

14:30         4256.     A Pattern Recognition Model for Automatic Classification of 1H MRSI Voxels in the Prostate

Lukasz Matulewicz1, Kristen L. Zakian1, Amita Shukla-Dave1, Jacobus F.A. Jansen1, Yousef Mazaheri1, Hedvig Hricak1, Jason Koutcher1

1Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA

A model is introduced for the automated pattern recognition (PR) of 1H MRSI data indicating tumor-suspicious voxels in the prostate to assist clinicians in cancer diagnosis. Spectra from 10 patients with prostate cancer were included.

15:00         4257.     Diffusion Weighted Imaging (DWI) of the Prostate Cancer at 3 T; Comparative Study with DWI at 1.5 T

Atsushi Nakamoto1, Hiromitsu Onishi1, Tonsok Kim1, Takahiro Tsuboyama1, Masatoshi Hori1, Yasuhiro Nakaya1, Noboru Maeda1, Hiroki Higashihara1, Mitsuaki Tatsumi1, Keigo Osuga1, Kaname Tomoda1, Hironobu Nakamura1

1Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan

The apparent diffusion coefficient (ADC) value, image quality and diagnostic performance of diffusion-weighted imaging (DWI) of the prostate at 3 T were compared with those at 1.5 T in forty patients. The ADC values at 3 T were almost equivalent to those at 1.5 T, and statistically significant correlation was seen between them. Image quality of DWI at 3 T was significantly superior to that at 1.5 T. Diagnostic performance of DWI at 3 T was superior to that at 1.5 T, but the difference was not significant.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 73

13:30         4258.     Volumetric 3D T2-Weighted Sequence of the Prostate (SPACE): Comparison with Conventional 2D T2 for Image Quality and Tumor Detection

Jeffry M. Neil1, Andrew Rosenkrantz1, Xiangtian Kong2, Jonathan Melamed2, Samir Taneja3, Herbert Lepor3, Bachir Taouli1

1Radiology, NYU Medical Center, New York, NY, USA; 2Pathology, NYU Medical Center, New York, NY, USA; 3Urology, NYU Medical Center, New York, NY, USA

The objective of our study was to compare a recently developed 3D T2WI sequence (SPACE) with conventional multiplanar TSE T2WI in terms of image quality, tumor detection and prostate-to-tumor contrast in prostate cancer patients undergoing prostatectomy. Our preliminary results (n=10) show that the SPACE sequence had equivalent subjective image quality, higher prostate-to-tumor ratio, and slightly higher accuracy for tumor detection, compared to conventional TSE T2WI. SPACE sequence may potentially be used as a replacement of conventional multiplanar T2WI, with the benefit of substantially shorter acquisition time.

14:00         4259.     Correlation of Gleason Score and Tumor Size with High Resolution 3T Magnetic Resonance Image-Detected Prostate Cancer

Elizabeth Genega Genega1, Nicholas Bloch2, William DeWolf3, R Elliot1, Y Fu1, Martin Sanda3, A Tomaszewski1, Andrew Wagner3, Ivan Pedrosa2, Neil Rofsky4

1Pathology, BIDMC, Boston, MA; 2Radiology, BIDMC, Boston, MA; 3Urology, BIDMC, Boston, MA; 4Radiology, BIDMC, Boston, MA, USA

Prostate cancer (PCa) detection has been rising since the implementation of serum prostate specific antigen screening and greater utilization of ultrasound guided prostate biopsy. However, many of those detected are low grade, low volume tumors that are clinically insignificant. In this work we demonstrate the sensitivity of high resolution 3T endorectal coil MRI in detecting clinically relevant PCa, using whole mount histopathology and tumor by tumor mapping as the reference standard.

14:30         4260.     Comparison of Unidirectional Diffusion Weighting with Isotropic Diffusion Weighting for the Detection of Prostate Tumors.

Marielle E.P. Philippens1, Taro Takahara2, Greetje Groenendaal1, Uulke A. van der Heide1

1Radiation Oncology, University Medical Centre Utrecht, Utrecht, Netherlands; 2Radiology, University Medical Centre Utrecht

Both isotropic and unidirectional diffusion weighting imaging (DWI) was applied and the effect on the determination of prostate cancer was studied to assess if unidirectional DWI improves the signal to noise and enables shorter measuring time. Both methods showed similar standard deviations. In the unidirectional ADC maps slightly lower ADC values and less pixels below a threshold of 0.9 10-3 mm2/s were found than in the isotropic ADC maps. In conclusion, unidirectional DWI did not lead to less noise in the ADC maps and therefore, did not enable shorter measuring times.

15:00         4261.     Changes in Dynamic Contrast Enhanced MRI Paramters in the First 8 Weeks of Prostate Radiotherapy

Masoom A. Haider1, Peter Chung2, Warren Foltz2, Anna Kirilova2, Charles Catton2, Padraig Warde2, Andrew Bayley2, Robert Bristow2, Michael Milosevic2, Cynthia Menard2

1Medical Imaging, University of Toronto, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada

Twelve patients underwent DCE MRI of the prostate prior and at 2, 4, 6, and 8 weeks during external bean radiotherapy. There was a significant moderate positive correlation between cumulative radiation dose and percent change in Ktrans, ve, and IAUCC60 for the whole prostate, peripheral zone and transition zone (0.53-0.69, p<0.0005). The overall pattern consisted of a maximal two week incremental increase occurring in the first 4 weeks during therapy. The 2-4 week period during the course of radiotherapy may be the best time to assess the potential prognostic value of DCE MRI.

 


 
MRS Methodology
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 74

14:00         4262.     Magnetic Resonance Spectroscopy with Receive Arrays: How to Combine the Signals

Christopher Thomas Rodgers1, Stefan Neubauer1, Matthew D. Robson1

1Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK

Array receive coils are ubiquitous for magnetic resonance (MR) imaging, improving the signal-to-noise ratio (SNR) and field of view. For MR spectroscopy, array coils are less well established and it is less obvious how signals from each element should be recombined. We present a Bayesian model of array spectroscopy where the maximum likelihood spectrum can be recovered using the well-known singular value decomposition. This simple and efficient algorithm is compatible with 1H and heteronuclear spectroscopy and does not necessitate tedious curve fitting procedures. We use 31P cardiac spectra from an eight-element array and numerical simulations to demonstrate its effectiveness.

14:30         4263.     SNR Improvement of MR Phased Array Spectroscopy Signals

Nicola Martini1, Matteo Milanesi2, Giulio Giovannetti3, Daniele De Marchi2, Vincenzo Positano2, Luigi Landini4, Maria Filomena Santarelli3

1Interdepartmental Research Center "E. Piaggio", University of Pisa, Pisa, Italy, Italy; 2Fondazione Toscana "G. Monasterio", Pisa, Italy; 3Institute of Clinical Physiology, National Research Council, Pisa, Italy; 4Deparment of Information Engineering, University of Pisa, Pisa, Italy

In this work we describe a novel method for the combination of MRS signals acquired by a phased array coil taking into account possible noise correlations. Performance evaluation was carried out on simulated 1H-MRS signals and preliminary experimental results were obtained on phantom 1H-MR spectra. Our approach could be usefully applied in high density phased arrays, where it results from literature that noise correlations increase with the number of coil elements.

15:00         4264.     Combination of Phased-Array Coil Signals in Localized 2D Correlated Spectroscopy: Artifacts and Remedies

Gaurav Verma1, Nagarajan Rajakumar, Aparna Singhal, Scott Logan Lipnick, Michael Albert Thomas

1Bioengineering, Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA

Conventional combination of phased-array coils can result in loss of phase information when post-processing two-dimensional spectroscopic data and the generation of multiple artificial parallel diagonals that overwhelm any off-diagonal signals. Two novel coil combination schemes that preserve phase information have been developed and tested using a variety of coils in both phantom and in vivo scans. These schemes have been proven effective in combining signals from multiple coils while avoiding phase loss and parallel diagonals. Data showing a single diagonal has been zero-phased to confirm the loss of phase information as the source of these parallel diagonal artifacts.

15:30         4265.     Dependence of Rotating Frame Relaxation Rates on Frequency Offset: Spin-Lock Versus Adiabatic Rotation

Silvia Mangia1, Timo Liimatainen1, Michael Garwood1, Shalom Michaeli1

1Radiology, University of Minnesota, Minneapolis, MN, USA

In the present work we investigate the frequency offset dependency of the rotating frame longitudinal, R, and transverse, R, relaxation rate constants during continuous-wave spin-lock irradiation and during hyperbolic secant adiabatic full passage pulses. We demonstrate, both theoretically and experimentally, that R and R induced by dipolar interactions and anisochronous exchange during hyperbolic secant pulses are minimally dependent on the frequency offset&#61472;&#61472;within the bandwidth of the pulse, as opposite to continuous-wave irradiation. This is a unique advantage for MRS applications in vivo, because it allows "one shot" data acquisition over a wide range of chemical shift.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 74

13:30         4266.     Whole-Brain N-Acetylaspartate Quantification: Performance Comparison of NAA Versus Lipid Nulling

Daniel Rigotti1, Jan Hovener1, Michael Amann2, Peter Bachert3, Achim Gass2, Oded Gonen1

1Radiology, NYU School of Medicine, New York, NY, USA; 2Neurology and Neuroradiology, University Hospital Basel, Basel, Switzerland; 3Division of Medical Physics, German Cancer Research Center, Heidelberg, Germany

Despite its prominent peak in 1H-MRS of the brain and its near exclusivity to neurons, the absolute amount of N-Acetylaspartate (NAA) is difficult to obtain due to signal contamination from skull lipids. Here we report the performance of two methods that overcome this problem to yield the whole-brain NAA signal (WBNAA). WBNAA was obtained from twelve volunteers with both a lipid- and NAA-nulling scheme. Despite being twofold quicker, the lipid-nulling technique had a higher intrinsic (5.8%vs8.6%) and longitudinal (10.6%vs19.7%) coefficient of variation when compared with NAA-nulling. Therefore, when time is critical, lipid-nulling is viable, otherwise, however NAA-nulling is more precise.

14:00         4267.     High-Resolution 2D MR Spectroscopy Via Intermolecular Multiple-Quantum Coherences

Xi Chen1, Meijin Lin1, Zhong Chen1

1Department of Physics, Xiamen University, Xiamen, Fujian, China

Three-dimensional intermolecular multiple-quantum coherence sequences are proposed to achieve high-resolution 2D MRS such as COSY and J-resolved spectroscopy under inhomogeneous fields. Delay acquisition and foldover correction schemes are utilized to reduce the scanning time of the 3D spectrum. Primary measurements are performed on phantoms under inhomogeneous fields to test the feasibility of the proposed sequences.

14:30         4268.     Proton MR Spectroscopic Imaging (MRSI) Metabolite Ratios in Human Brain: Calculating Repeatability When Measurement Error Is Proportional to the Mean

David John Manton1, Gary Paul Liney1, Roberto Garcia-Alvarez2, Lindsay W. Turnbull1

1YCR Centre for MR Investigations, Hull, East Yorkshire, UK; 2GE Healthcare, Madrid, Spain

NAA:choline peak area ratios were measured in the brains of eight healthy volunteers at 3T using PRESS MR spectroscopic imaging with the acquisitions carried out twice during the same examinations in order to allow repeatability to be quantified. Measurement error was found to be proportional to the mean which meant that simple repeatability limits (e.g. mean +/- 1.96 x standard deviation) would be inappropriate given that precision varied with mean. Measurement error was not proportional to the mean after the use of the square root of the inverse data transformation and this allowed appropriate (non-constant) repeatability limits to be calculated.

15:00         4269.     Biochemical, Anatomical and Neuropsychological Correlates in Hepatic Encephalopathy

Aparna Singhal1, Charles Hinkin2, Nagarajan Rajakumar1, Rajesh Kumar3, Amir Huda1,4, Steven-Huy B. Han5, Virginia Elderkin-Thompson2, James W. Sayre1,6, Rakesh K. Gupta7, Michael Albert Thomas1

1Radiology, UCLA, Los Angeles, CA, USA; 2Psychiatry & Biobehavioural Sciences, UCLA, Los Angeles, CA, USA; 3Neurobiology, UCLA, Los Angeles, CA, USA; 4Physics, California State University, Fresno, CA, USA; 5Medicine, UCLA, Los Angeles, CA, USA; 6Public Health- Biostatiscs, UCLA, Los Angeles, CA, USA; 7Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, UP, India

The frontal and occipital white/gray matter regions were investigated in 34 minimal hepatic encephalopathy (MHE) patients and 30 controls using single-voxel-based 2D L-COSY. Globus pallidal signal-intensities were calculated and neuropsychological tests (NPT) were performed on the same day. There was significant elevation of combined glutamate and glutamine to creatine ratios, as well as reduction in choline, taurine and myo-inositol compared to controls. 2D MRS ratios including taurine correlated strongly with NPTs indicating their role in the pathogenesis and mICh/Cr_d ratio gives the best diagnostic predictability in differentiating MHE patients from controls compared to NPTs or MRI alone.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 74

13:30         4270.     Improving Spectral Resolution of Proton MRSI by Deconvolving Field Inhomogeneities

Zhengchao Dong1,2, Bradley Peterson1,2

1Columbia University, New York, NY, USA; 2New York State Psychiatric Institute, New York, NY, USA

The resolution of in vivo 1H MRSI spectra is often degraded by magnetic field inhomogeneities, making the quantification of metabolites with overlapping spectral peaks difficult or impossible. In this work, a novel post-processing method is proposed that can significantly ameliorate the deleterious effects of magnetic field inhomogeneities, thereby enhancing the resolution of MRSI spectra. The method is demonstrated and validated using phantom and in vivo experiments. The results show that this method not only enhances spectral resolution, but it also improves the lineshape of MRSI spectra.

14:00         4271.     High-Resolution MRS Via Intermolecular Double-Quantum Coherences in Fields Inhomogeneous in Both B0 and B1

Yanqin Lin1,2, Congbo Cai1, Shuhui Cai1, Zhong Chen3, Jianhui Zhong2

1Physics Department, Xiamen University, Xiamen, Fujian, China; 2Imaging Sciences, University of Rochester, Rochester, NY, USA; 3Physics Department, Xiamen University, Xiamen , Fujian, China

Inhomogeneous B0 and B1 fields are inevitable under some circumstances, and are obstacles for high-resolution magnetic resonance spectroscopy (MRS). Here we show that the effects of inhomogeneous B0 and B1 fields can be almost completely removed via detection of intermolecular double-quantum coherences, while retaining the high-resolution information of chemical shifts, multiplet patterns, J coupling constants and relative peak areas.

14:30         4272.     A Novel Hybrid Method for Applying Independent Component Analysis to in Vivo Paediatric Brain Tumour 1H Magnetic Resonance Spectra

Jie Hao1, M P. Wilson2, N P. Davies2,3, Y Sun2,4, K Natarajan3,4, L MacPherson4, A C. Peet2,4, T N. Arvanitis1,4

1School of Electronic, Electrical & Computer Engineering, University of Birmingham, Birmingham, UK; 2School of Cancer Sciences, University of Birmingham, Birmingham, UK; 3Department of Imaging and Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; 4Birmingham Children’s Hospital NHS Foundation Trust, Birmingham, UK

Independent Component Analysis (ICA) has shown the possibility to identify the individual components, and reveal hidden biochemical information about the tissues in MRS. A hybrid ICA approach incorporating the Blind Source Separation (BSS) and Feature Extraction (FE) techniques for automated decomposition of MR spectra is developed and applied to an in vivo paediatric brain tumour MRS dataset. The hybrid method of ICA has the advantages of both BSS and FE, and provides more realistic individual metabolite and MMLip components. It is superior to the well established IC techniques in determining individual metabolite components from brain tumour MRS.

15:00         4273.     Improved Spectral Resolution in 2D Localized Correlated Spectroscopy Using Enhanced Covariance NMR

Neil Wilson1, Enrique Frias-Martinez1, Michael Albert Thomas1

1Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA

Resolution along the indirect dimension (t1) is limited by the number of increments used for achieving the 2nd spectral axis in localized 2D MRS, thus leading to lower resolution along t1 compared to the detected dimension (t2). Covariance NMR has been extended to processing the 2D data to achieve equal resolution along both spectral dimensions (F2, F1) even though 2-3% of t2 points were only used for t1. While using limited t1 points, occurrence of false cross peaks was minimized using an enhanced covariance NMR method and pilot evaluations using phantom solutions and in vivo brain show promising results.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 74

13:30         4274.     Relaxation Time Measurements of 31P Metabolites in the Human Calf Muscle at 7 Tesla

Wolfgang Bogner1, Marek Chmelik2, Albrecht Ingo Schmid2, Ewald Moser, Siegfried Trattnig1, Stephan Gruber1

1Radiology, MR Center of Excellence, Medical University Vienna, Vienna, Austria; 2Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria

Phosphorus (31P) MR spectroscopy is a useful tool for non-invasive investigations of human muscle metabolism under various physiological and pathological conditions. In order to optimize measurement parameters (TR, TE) of spectroscopy sequences and for absolute quantification of metabolitesaccurate knowledge of T1 and T2 are necessary. Relaxation times may vary for different metabolites and with the magnetic field strength (B0). With the advent of 7 Tesla systems the need for accurate relaxation times of 31P metabolites will evolve. Our results found for T1 times at 7T are similar to those reported previously at 3T and below. However, a decrease in T2 values can be observed. The method is considerably robust to B1 inhomogeneities and easily applicable to other parts of the body.

14:00         4275.     In Vivo Animal NMR Studies Using Implantable Micro-Coil

Aziz Kadjo1, Nicoleta Baxan2, Raymond Cespuglio3, André Briguet1, Colette Rousset3, Minh Dung Hoang1, Danielle Graveron-Demilly1, Latifa Fakri-Bouchet1

1CREATIS-LRMN, UMR CNRS  5220, INSERM U 630, INSA de Lyon, Université Lyon 1, Villeurbanne, France; 2Medical Physics Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany; 3Laboratoire «Radicaux libres/substrats énergie et physiopathologie cérébrale.» EA 4170, Université Lyon1,, France

The feasibility to use a new generation of micro-coils was proposed in a recent study. It demonstrated to have potential opportunities in terms of increased signal-to-noise ratio (SNR), spatial resolution, and limits of detection (LOD), compared to the surface-coil. The originality of the present work is to show how to realize brain implantable NMR detectors, tolerated by rats for several weeks. To the best of our knowledge, no in vivo study has been already done with such sensors. Reinforced by acquisition and signal processing, it aims at pushing the limits of in vivo detection and an ultra localisation technique should result from this approach.

14:30         4276.     Differentiation Between Brain Metastasis and Glioblastoma Using MRI and Two-Dimensional Turbo Spectroscopic Imaging Data

Jan Luts1, Teresa Laudadio1,2, M.Carmen Martínez-Bisbal3,4, Bernardo Celda3,4, Sabine Van Huffel1

1Department of Electrical engineering, Division ESAT-SCD, Katholieke Universiteit Leuven, Leuven, Belgium; 2Istituto per le Applicazioni del Calcolo “M. Picone”, National Research Council, (IAC-CNR), Bari, Italy; 3Departamento de Química-Física, Facultad de Química, Universidad de València, València, Spain; 4CIBER of Bioengineering, Biomaterials and Nanomedicine, ISC-III, Spain

In spite of the significant progresses achieved in the field of MRI in the last decades, the differentiation between brain metastasis and glioblastoma is still a challenge since conventional MRI alone cannot always differentiate the two tumor types, while they require a completely different therapeutic treatment. Previous studies have shown that, in contrast to metastases, the peritumoral region in glioblastomas contains infiltrating tumor cells. This study explores the combination of MRI and two-dimensional Turbo Spectroscopic Imaging to distinguish the aforementioned tumors and proposes a novel classification method based on nosologic images, allowing a visual differentiation between metastasis and glioblastoma lesions.

15:00         4277.     Performance of the Steighlitz-McBride Algorithm for Spectral Parameter Estimation from a Rapid Multi-Gradient Echo Acquisition

Brian A. Taylor1, Ken-Pin Hwang2, John D. Hazle1, Roger Jason Stafford1

1Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Applied Science Laboratory, GE Healthcare, Waukesha, WI

The performance of the Stieglitz-McBride algorithm using a limited number of echoes (<16) returned from a fast chemical shift imaging sequence for accurate and precise determination of spectral parameters is investigated in one and two peak systems. The chemical shift and amplitude uncertainties reaching the Cramer-Rao Lpwer Bound over a wide range of SNR values and ETL lengths along with accurate and precise T2* measurements at higher SNR and ETL values. Results were corroborated by phantom measurements. The accuracy and precision of this technique in resolving fat and water shifts make it attractive for monitoring of dynamic processes such as thermal therapies and chemical ablations.

 


 
Spectroscopy Acquisition & Quantification
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 75

14:00         4278.     Quantification of Short-TE Metabolite Signals in Human Brain Using QUEST and a Simulated Basis Set

Hyeon-Man Baek1, Sergey Cheshkov1,2, Audrey J. Chang1, Richard W. Briggs1,2

1Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA; 2Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA

In this study, in vivo quantification of short-TE metabolite signals measured in the basal ganglia was performed with QUEST (using jMRUI software) using a simulated metabolite basis set. The measured metabolite concentrations in this work were consistent with the reported values in the literature (Govindaraju et al.). Our results suggested that six metabolites (NAA, Ins, Cr, Cho, Glu, and Glx) can be reliably quantified in human basal ganglia (voxel size, 2x3x2 cm3) at short TE at 3T. However, it was not possible to quantify other metabolites such as GABA CRLB = 33%) and Gln (CRLB = 58%). <

14:30         4279.     The Quantitative Comparison of Doing Eddy Current Correction Before and After Combination for 1H MRS Using Phased Array Coils with LCModel

Lung-Sheng Chang1, Cheng-Wen Ko1, Shang-Yueh Tsai2, Tzu-Chao Chuang3, Cheng-Yun Hsu1

1Dept. of Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan; 2Dept. of Electrical Engineering, Chang Gung University, Tao-Yuan, Taiwan; 3Dept. of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan

The purpose of this study is to demonstrate the importance of doing eddy current correction for each coil element before combination for phased array MRS data, and validate the reliability and accuracy in terms of SNR and absolute concentrations of MRS in vivo. Our result shows that there is no difference in terms of SNR for the spectra doing eddy current correction before and after combination. However, doing eddy current correction before combination of each channel data will improve the accuracy of absolute concentrations and benefit the multi-center comparison in clinical applications.

15:00         4280.     Exploiting Spatial Information for Estimating Metabolite Concentration in MRSI

Anca Croitor Sava1, Diana Sima1, Jean Baptiste Poullet1, Sabine Van Huffel1

1Department of Electrical Engineering, Division ESAT-SCD, Katholieke Universiteit Leuven, Heverlee, Belgium

AQSES-MRSI is a new quantification method for MRSI data, which exploits spatial prior knowledge. During an MRSI acquisition, MR spectra are measured in a grid of voxels. In AQSES-MRSI the assumption is that adjacent voxels should have signals with similar spectral parameters and therefore the signal from each voxel is quantified using information coming from the spectral parameters (frequency shifts, damping corrections, phase shifts, etc) of the surrounding voxels.

15:30         4281.     Statistical Methods to Determine the Reliability of in Vivo Single Voxel MRS Data

Johannes Slotboom1, Dirk van Ormondt2

1Neuroradiology, Univeristy Hospital and Inselspital, Bern, Switzerland; 2Applied Physics, Delft University of Technology, Delft, Netherlands

Spectral quality and spectral reliability are closely related, but not identical. Although MRS-signal reliability is an issue of highest importance, its notion received, to the best of the authors’ knowledge, no systematic treatment in the in vivo MRS-literature in the past. Frequently it remains unclear whether clinical in vivo single voxel data MRS data can be trusted, i.e., can be used for diagnostic purposes. In order to make SV-MRS clinically more viable, assessment of spectral reliability of the data should preferably be handled by the MR-scanner system rather than by medical staff. In this contribution, we devise, apply, and test statistical methods for automated data reliability testing. Once the data pass the reliability test, the MRS signal is considered reliable and the variances of the maximum likelihood (ML) estimated parameters approach the Cramér-Rao minimum variance bound (CR-MVB).

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 75

13:30         4282.     Systematic Error in the Measurement of [GABA]/[Cr] Ratio Using Methyl Resonance of Creatine

Pallab K. Bhattacharyya1

1Imaging Institute, Cleveland Clinic, Cleveland, OH, USA

While using J-difference editing in GABA measurement, tt is a common practice to report [GABA]/[Cr] ratio by measuring the areas under the 3.01 ppm CH2 (C-4) GABA peak in the edited spectrum and the 3.03 ppm CH3 creatine (Cr) peak in the unedited spectrum. We have shown that this way of measuring [GABA]/[Cr] ratio will introduce a systematic error, and we propose the use of the 3.93 ppm CH2 Cr peak for this purpose. The source of this error is the contribution of 3.01 ppm GABA triplet to the total area under the 3.03 ppm Cr peak

14:00         4283.     PRESS Spectroscopy of Glutamate: Effects of Voxel Location and Field Strength

Jean D. Jutras1, Chris C. Hanstock1, Jeff Snyder1, Alan H. Wilman1

1Dept. of Biomedical Engineering, University of Al berta, Edmonton, Alberta, Canada

For PRESS spectroscopy of glutamate in the human brain, the choice of field strength can play a large role in affecting the optimal timings and yields, however, the voxel location (occipital lobe, frontal lobe or midbrain) is also critical to consider since susceptibility effects from tissue-air and tissue-iron interfaces play an increasing role with increasing field. We assess these effects for a range of field strengths.

14:30         4284.     Turbo-Spin-Echo Based Correlated Spectroscopic Imaging of Breast Tissues in Vivo: A Preliminary Study

Xiaoyu Liu1, Gaurav Verma2, Scott Lipnick1, Sasd Ramadan3, Nanette Debruhl1, Michael Albert Thomas1

1Radiology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA, USA; 2Biomedical Energing, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA, USA; 3Harvard Medical School, Boston, MA, USA

Magnetic Resonance Spectroscopy (MRS) studies have detected differences in metabolite concentrations in healthy breast tissues and lesions non-invasively. Two-dimensional (2D) MRS has improved resolution compared to one-dimensional (1D) MRS due to the additional J-coupling information in the second dimension. Single voxel (SV) MRS has limitations in terms of breast coverage. Multi-dimensional MR spectroscopic imaging 2 spatial + 2 spectral solves the problem by generating different metabolic images. In this study we demonstrate the feasibility of evaluating a 4-echo based Turbo-Spin-Echo Correlated Spectroscopic Imaging (TSE-COSI) sequence acquiring multi-voxel based 2D COSY of breast tissues in vivo.

15:00         4285.     Reproducibility of 3D 1H MR Spectroscopic Imaging of the Prostate at 1.5T.

Tom WJ Scheenen1, Jurgen J. Fütterer1, Elisabeth Weiland2, Jaoping Lu3, Barbara Holshouser4, Paul van Hecke5, Marc Lemort6, Christian M. Zechmann7, Heinz-Peter Schlemmer8, Geert M. Villeirs9, Jelle O. Barentsz1, Stefan O. Roell2, Arend Heerschap1

1Radiology (667), Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 2Siemens Healthcare; 3Shanghai Changhai Hospital, China; 4Loma Linda University Medical Centre, USA; 5University Hospital, Katholieke Universiteit Leuven, Belgium; 6the Bordet Institute, Belgium; 7German Cancer Research Center DKFZ, Germany; 8University of Tuebingen, Germany; 9Ghent University Hospital, Belgium

Within the IMAPS study (International Multi-Centre Assessment of Prostate MR Spectroscopy) the reproducibility of 3D 1H-MRSI at a field strength of 1.5T was evaluated by repeated measurements of patients and healthy young volunteers. Ten subjects were measured twice on 2 different days. Selected voxels of the same location in both measurements were fit automatically and visually inspected for quality control. The bias and corresponding standard deviation of a Bland Altman analysis of the (choline+creatine)/citrate ratio of these voxels were calculated. The standard deviation of differences in repeated measurements was similar to the standard deviation of non-cancer peripheral zone tissue in patients with prostate cancer.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 75

13:30         4286.     Comparison Between Internal and External Validation of in Vivo 31P MRS Quantification

Jon Dudley1, Wen-Jang Chu2,3, Xin Wang1, Matthew M. Norris1, Jing-Huei Lee1,3

1Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA; 2Psychiatry, University of Cincinnati, Cincinnati, OH, USA; 3Center for Imaging Research, University of Cincinnati, Cincinnati, OH, USA

Internal references are commonly used in in vivo MRS research. However, an internal reference for 31P MRS study may not be practical. This works is to investigate if an external reference can be reliable method for 31P MRS data by comparing its result with that obtained by an internal reference from 1H MRS data. The results showed that there is a strong correlation between these two approaches indicating that an external reference can be a reliable method.

14:00         4287.     Absolute Quantification of ATP and Other High Energy Phosphate Compounds in Cat Brain at 9.4T

Xiao-Hong Zhu1, Yi Zhang1, Wei Chen1

1CMRR, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA

Absolute quantification of metabolite concentrations noninvasively has been a long-standing challenge for many researchers in the in vivo NMR field. Despite substantial efforts and some progresses, it is generally believed that the accuracy of such quantification was limited due to the large systematic error introduced by various calibration techniques. After careful comparison of different calibration approaches reported in the literature for absolute quantification of high energy phosphate (HEP) concentrations using in vivo 31P MRS, we have come up with our own, improved experimental design which eliminates most systematic errors and provides reliable quantification results for ATP and other HEP compounds in cat brain at 9.4T.

14:30         4288.     Novel 31P Saturation Transfer Strategy for Measurement of Chemical Exchange Reaction Kinetics in Vivo

Qiang Xiong1,2, Qinglu Li3, Abdul Mansoor3, Fei Du2, Wei Chen2,4, Jianyi Zhang1,3

1Dept. of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA; 3Dept. of Medicine, University of Minnesota, Minneapolis, MN, USA; 4Dept. of Radiology, University of Minnesota, Minneapolis, MN, USA

A novel strategy is presented for further improving the steady-state magnetization saturation transfer (ST) method in measuring chemical exchange reaction kinetics in vivo. The strategy is based on numerical simulation of Bloch equations to optimize both the pre-saturation delay and saturation time in order to rapidly achieve steady-state magnetization for chemically coupled phosphate metabolite. The new approach was validated in the swine heart model in vivo for determining the forward rate constant of myocardial creatine kinase reaction and showed substantial reductions in both saturation time (by 56 %) as well as total repetition time (by 75 %) as compared to conventional approach. The results demonstrate the great potentials for biomedical applications including on human study.

15:00         4289.     Enhanced In-Vivo C13 Spectroscopy Using Adiabatic INEPT Sequences and Custom-Made RF Coils

Ovidiu C. Andronesi1, Dionyssios Mintzopoulos1,2, Hellmut Merkle3, A Aria Tzika1,2

1Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA; 2NMR Surgical Laboratory, MGH & Shriners Hospitals, Harvard Medical School, Boston, MA, USA; 3National Institutes of Health, Laboratory of Functional and Molecular Imaging, Bethesda, MD, USA

We report significant C13 spectroscopic signal enhancement in vivo using an optimized adiabatic INEPT sequence (BINEPT, with BIR-4 pulses) and a custom-made high-quality RF coil, at high field (9.4 T).

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 75

13:30         4290.     Chemical Shift Change Shows Spatial Orientation of Lipids in Human Brain

Albert J.S. Idema1, Jannie P. Wijnen2, T. Scheenen2, M. van der Graaf2, A. Heerschap2

1Neurosurgery, UMC St Radboud, Nijmegen, Gelderland, Netherlands; 2Radiology, UMC St Radboud, Nijmegen, Netherlands

In a patient with an intracranial lipoma we performed 3D MR spectroscopic imaging with the head positioned in 3 different sagittal orientations with respect to the main magnetic field and observed for the first time an angular dependent shift and broadening of signals from lipids in human brain in this lipoma. Signals of other metabolites and lipids from a malignant intracranial tumor in the same patient were not affected. The magnitude of the signal changes are very similar to that observed for extramyocellular lipid signals in muscles and thus suggest a similar structural orientation of lipids in the lipoma.

14:00         4291.     Quantum-Mechanical Generalization of the Extended Phase Graph Method (QuaM-EPG) for the Simulation of Coupled Spin Systems Under SSFP Excitation

Zenon Starcuk jr. 1, Jana Starcukova1, Oliver Strbak1, Danielle Graveron-Demilly2

1MR & Bioinformatics Dept., Institute of Scientific Instruments, AS CR, Brno, Czech Republic; 2INSERM U630, Creatis-LRMN, CNRS UMR 5220, Villeurbanne, France

A method suitable for the computer simulation of coupled spin systems under steady-state free precession (SSFP) excitation for fast MR spectroscopic imaging is described and demonstrated. The new method applies the principles of Hennig's Extended Phase Graph method to standard quantum mechanics employing the density matrix formalism, with relaxation described by the Redfield matrix. Thanks to the enhancement, balanced or nonbalanced (S+, S-) SSFP signals can be calculated. The calculation is basically a superstructure above the standard density-matrix simulation, no analytical preparation or complex programming are required. This approach can be useful also for analyzing SSFP with selective excitation.

14:30         4292.     New Technology: Mass Balance Phenotyping

Peter Pediatitakis1, Jason H. Winnike1, Justyna Wolak2, Kayvan R. Keshari1, Rex E. Jeffries1, Ryan Webb1, Greg Young3, Haakil Lee1, Michael P. Gamcsik1, Lee M. Graves4, Paul B. Watkins4, John Kurhanewizcz5, Jeffrey M. Macdonald1

1Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA; 2Liposcience Inc., Raliegh, NC, USA; 3Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA; 4Pharmacology, University of North Carolina, Chapel Hill, NC, USA; 5Radiology, University of California, San Francisco, CA, USA

We report a novel metabolomic method, mass balance phenotyping, which is based on compartmental analysis and uses empirical NMR data as input. The method employs u-13C-glucose and u-13C-glutamine to quantify metabolic flux. The pharmacodynamics (i.e., effect of drug on metabolism) is demonstrated using 2-dimensional (2D) rat hepatocytes cultured over a 48 hr period demonstrating the well-known metabolic trans-differentiation process. A rat liver cell-line (JM1) is used as a comparison. The pharmacokinetics is demonstrated using acetaminophen (APAP) exposure to 2D primary human hepatocyte cultures. The boundary conditions of the metabolic network is the interface between the cells and the media.

15:00         4293.     An RF-Over-Fiber System for Reliable Signal Injection in ERETIC Spectroscopy

Matteo Pavan1, Susanne Heinzer - Schweizer1, Nicola De Zanche1,2, Anke Henning1, Peter Boesiger1, Klaas Paul Pruessmann1

1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 2Department of Medical Physics, Cross Cancer Institute and University of Alberta, Canada

We present an optical link used to transmit a reference signal in spectroscopy (ERETIC method). The optical link has the peculiarity to be safety and inexpensive since it is made of only a low noise preamplifier, a high speed LED, polymer optical fiber and a photodiode. The reference signal is generated outside the MR room, it travels along the optical fiber, enters the scanner room’s Faraday shield through a waveguide and is injected into a birdcage coil by inductive coupling. The link is shown to be reliable and stable over time consenting so, good fidelity quantitative measurements of metabolite concentrations.

 


 
MRS of Cells Body Fluids Other
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 76

14:00         4294.     Detection of Serine Isotopomers as a Measure of Mitochondrial Function

Christopher Bryce Johnson1, Peter Pediaditakis1, Andrey Tikunov1, Douglas Romney2, Haakil Lee1, Ekhson Holmuhamedov2,3, Mike Gamcsik4, Jeffrey MacDonald1

1Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 2Cell Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 3The Center of Theoretical Problems of Physico-Chemical Pharmacology, Moscow, Russian Federation; 4Biomedical Engineering, North Carolina State University, Raleigh, NC, USA

The glycine cleavage system (GCS), which is found exclusively in mitochondria, converts glycine to methylene tetrahydrofolate (mTHF), and serine hydroxymethyltransferase (SHMT) uses the mTHF to form serine. A SHMT isoform also exists in the cytosol. When 2-13C glycine is used in place of unlabeled glycine, two pools of serine are formed, a 3-C labeled serine from the mitochondria and a 2-C labeled serine from the cytosolic. We show that MRS can detect the resulting serine pools, and we hypothesize that by analyzing these pools this method can be uses as a non invasive, in vivo detection system of mitochondrial function.

14:30         4295.     Application of Stable Isotope Labelling in Cell Culture Experiments: [2-13C]pyruvate as Novel and Superior Substrate for in Vitro Metabolic Studies in Primary Mouse Hepatocytes

Sven Gottschalk1, Dieter Leibfritz2, Claudia Zwingmann1,2, Marc Bilodeau1

1Département de sciences biomédicales, Université de Montréal, Montréal, Québec, Canada; 2Department of Organic Chemistry, University of Bremen, Bremen, Germany

Application of stable isotope labeling in vitro is a potent technique to study metabolic pathways and fluxes. We applied [2-13C]pyruvate on primary mouse hepatocyte cultures to compare its usefulness for metabolic studies and flux analysis with other labeled substances. Our results show: [2-13C]pyruvate was metabolized by lactate dehydrogenase, alanine-/aspartate-aminotransferase, malic enzyme, PC, PDH and subsequent metabolic pathways through the TCA-cycle. Taken together with our previous findings, we conclude that [2-13C]pyruvate is a versatile physiological substrate to study hepatocellular pathways and the de novo synthesis of major metabolites in these cells under normal and pathological conditions.

15:00         4296.     Mass Balance Phenotyping of Primary Human Hepatocytes in 2D Cultures Treated with Acetaminophen

Jason Hyun Winnike1, Peter Pediaditakis1, Paul Brent Watkins2, Jeffrey Marshall Macdonald1

1Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA; 2Medicine, University of North Carolina, Chapel Hill, NC, USA

Primary human hepatocytes were treated with non-cytotoxic doses of acetaminophen to examine its effects on metabolism and metabolite profiles. After exposure to cell media containing acetaminophen and u-13C glucose, hepatocytes were extracted so that the polar small molecule intracellular metabolites could be collected for NMR spectroscopy. Endogenous and exogenous phase 2 metabolites were identified and quantified using the NMR spectra. This information was used to examine how primary human hepatocytes metabolized the xenobiotic as well as determine changes in endogenous metabolism indicative of changes in energy production and storage.

15:30         4297.     Protective Effect of Hypothermia on Ammonia Toxicity and Energetic Disturbances in Astrocytes

Jessica Heins1, Dieter Leibfritz1, Claudia Zwingmann1,2

1Department of Organic Chemistry, University of Bremen, Bremen, Germany; 2Centre de Recherche, Hospital Saint-Luc, Montreal, Quebec, Canada

Ammonia causes cell swelling and energy failure of astrocytes in hepatic encephalopathy (HE). Since mild hypothermia is known to offer protection from encephalopathy in HE, we investigated if hypothermia protects against ammonia-induced energy failure in cultured astrocytes, the major target in HE. Mild and moderate hypothermia attenuated the depletion of high-energy phosphates and prevented severe lactate accumulation. Mitochondrial glucose flux contributing to glutamine synthesis decreased, while direct conversion of glutamate and ammonia to glutamine was still significantly elevated. The results suggest that hypothermia-induced protection against ammonia toxicity results from reduced energy demands in reactions uncoupled from mitochondrial energy metabolism.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 76

13:30         4298.     Optimisation and Evaluation of Diffusion-Weighted Magnetic Resonance for Assessing Mobile Lipid Resoanances in Cancer

Dominik Zietkowski1, Thomas R. Eykyn1, Nandita M. deSouza1, Geoffrey S. Payne1

1Cancer Research UK Clinical Magnetic Resonance Research Group, The Institute of Cancer Research, Sutton, Surrey, UK

Measuring mobile lipid resonance changes in 1H NMR spectra of cell pellets and tissues are confounded by signals from low molecular weight metabolites which complicate peak assignment and quantification. A simple and effective approach is to use diffusion-weighted sequences (DW) to attenuate the low molecular weight metabolites based on their relatively high diffusion coefficients. We have optimised a stimulated echo sequence with bipolar gradients to obtain diffusion-weighted HR-MAS spectra of model lipid solutions, cell pellets and cervical tissue samples, in order to characterise and validate the nature of the observed lipid chains in cancer cells in vitro and ex vivo.

14:00         4299.     High Resolution MR Spectroscopy Reveals Radiation Induced Metabolic Changes in Mouse Liver Tissues

Poonam Rana1, Ahmad Raza Khan1, Poonam Singh1, Shubhra Chaturvedi2, Rajendra Prasad Tripathi3, Subash Khushu1

1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 2Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 3INMAS, Delhi, India

Many NMR based studies have been carried out on liver metabolic status under different chemical or environmental toxic conditions. Our study was planned to find radiation induced changes in hepatic tissue on mice after radiation exposure using 1H NMR spectroscopy. Significant changes were observed after 25 days of exposure in protein/amino acid and energy metabolism and membrane structure alteration as evident from increased branched amino acids, alanine, lysine lactate, choline and myo inositol levels. Such findings support the potential use of metabolomic approach for identification of radiation induced injury in liver.

14:30         4300.     Exploration of the Effect of Whole Body Ionising Radiation Exposure on the Metabolism of Renal Tissue in Mice Using High Resolution 1H NMR Spectroscopy

Poonam Rana1, Ritika Agarwal1, Ahmad Raza Khan1, Shubhra Chaturvedi2, Rajendra Prasad Tripathi, Subash Khushu1

1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 2Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India

Ionising radiation has noticeable effect on physiology of the living systems. The present study was conducted to assess radiation induced changes in kidney tissue of mice after radiation dose of 5Gy and monitor changes after 5 and 25 days of irradiation using high resolution NMR spectroscopy. Significant changes were observed only after 25 days of exposure in protein/amino acid metabolism, energy metabolism and membrane structure alteration as shown by increased free amino acids, lactate, choline and myo-inositol levels. This study could be helpful for identification of potential biomarkers associated with radiation induced changes and may find applications in biological dosimeters.

15:00         4301.     Increasing Indices of Bile Constituents Following Decompression Therapy Are Indicators of Restorative Function of Hepatocytes: 1H and 31P NMR Studies<

Pratima Tripathi1, Lakshmi Bala1, Gourdas Choudhuri2, C. L. Khetrapal1

1CBMR, Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

1H and 31P NMR analysis on bile, obtained serially following drainage from nineteen patients with extrahepatic malignant biliary obstruction were performed for chief biliary constituents. Based upon absence or presence of cholangitis, patients were classified in two groups. Before drainage median indices of biliary constituents were undetectable in both groups but, recovery following decompression was observed by day 1, with more significance in patients with cholangitis compared to without cholangitis. However, values significantly increased following one week of drainage (P<0.05) in both groups. Suppressed function of transporters during cholestasis is restored following decompression leading to the appearance of biliary constituents.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 76

13:30         4302.     The Effect of PH on the Analysis of 1H MRS Data of Urine in Biomedical Applications

Omkar B. Ijare1, Tom Blydt-Hansen2, Tedros Bezabeh1

1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2Pediatric Nephrology, Children's Hospital, University of Manitoba, Winnipeg, Manitoba, Canada

Urine analysis by 1H NMR spectroscopy is widely used for the study of various disease processes. The chemical shifts of the key metabolites in urine such as citrate, creatinine, and trimethylamine N-oxide are pH-dependent, which can make reliable analysis of 1H NMR spectroscopic data difficult. Urine pH can vary over the range 4.6 - 8.0 under physiological stress. In the present study, we examined the effect of pH on the chemical shifts of above metabolites and found that adjusting the pH of urine to 7.1 ± 0.2 is essential for the reliable classification of 1H NMR spectroscopic data of urine in biomedical applications.

14:00         4303.     Proton NMR Spectroscopic Analysis of Pus for Differentiation Between Amoebic and Pyogenic Liver Abscesses

Santosh Kumar Bharti1, Virendra Jaiswal2, Ujjala Ghoshal2, Raja Roy1, S K. Mandal1, S S. Baijal3, U C. Ghoshal4, C L. Khetrapal1

1CBMR, Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 3Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 4Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

Hepatic abscesses with different types of infection such as bacterial and parasitic provide a challenging task for easier and early differentiation between such infections. PCR, Culture and 1H NMR analysis of pus were carried out on 118 patients with hepatic abscess. The 1H NMR spectroscopic analysis provided distinctive characterization of metabolites, viz., asparagine and aspartic acid in amoebic liver abscess, while pyogenic abscess showed the presence of acetate, succinate and formate. The NMR results reported herein have the advantage that the measurement can be rapidly performed in single step rather than two separate tests for bacterial and parasitic infections.

14:30         4304.     MRS of Neuronal Progenitor Cells in Vivo

Wolfgang Weber-Fahr1, Jens Benninghoff2, Kai Schönig3, Gabriele Ende4, Sascha Sartorius1

1RG Translational Imaging, Central Institute of Mental Health, Mannheim, Germany; 2Department of Psychiatry and Psychotherapy, University of Munich, Munich, Germany; 3Department of Molecular Biology, Central Institute of Mental Health, Mannheim, Germany; 4Department Neuroimaging, Central Institute of Mental Health, Mannheim, Germany

Lately Manganas et. al used 1H-MRS to investigate neural progenitor cells (NPCs) in vitro and. detected a peak at 1.28 ppm which they did not find in other cultured neural cell types. This study aims to inquire this resonance by measuring the 1H MRS signal of living NPC cell cultures. 18-20 Mio NPCs were measured on a 9.4T animal scanner in growth medium. We could not find a resonance line at 1.28ppm but a triplet at 1.21 ppm which might originate from Ethanol.

15:00         4305.     NAFLD Metabolic Signatures by HR-MAS Molecular Profiling

Jose Manuel Morales1, Juan del Olmo2, Jose Manuel Rodrigo2, Bernardo Celda1,3, Daniel Monleon4

1Universidad de Valencia; 2Hospital Clinico Universitario Valencia; 3CIBER-BBN; 4Fundacion Investigacion Hospital Clinico Universitario Valencia, Valencia, Spain

The liver plays a critical role in fat storage and retrieval. NAFLD is associated with an increase in lipogenesis and a decrease in the ability of the liver to export lipids. Global molecular profiles may reflect the presence of a particular disease state. In this study, we show that metabolites closely related to the liver metabolism like lipids and amino acids display differences between tissue from fatty liver with and without inflammation. This study shows that steatosis and steatohepatitis produce metabolic alterations identifiable by HRMAS spectroscopy. Our results may be the basis for using HRMAS of liver biopsies as support for tissue classification.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 76

13:30         4306.     NMR Based Metabonomic Investigation on the Biochemical Effects Induced by Radiation Exposure in Mouse Serum

Ahmad Raza Khan1, Poonam Rana1, Shubhra Chaturvedi2, Rajendra Prasad Tripathi3, Subash Khushu1

1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 2Division of Cyclotron and Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 3INMAS, Delhi, India

A high resolution 1H NMR spectroscopy based metabonomic approach has been used for finding biochemical alterations in serum as induced by radiation exposure. Blood samples were collected from mice after five days of radiation dose of 3 and 5 Gy. The proton NMR spectral analysis of serum presented the elevation of Branched amino acids, alanine, propionate and creatine and decreased concentration of lactate and choline in irradiated mice. These findings indicated enhanced protein breakdown, gluconeogenesis and altered lipid metabolism. Such metabonomic signatures may help in designing protocols and novel methodologies for screening at risk populations and measuring radiation dose.

14:00         4307.     NMR-Based Metabolomics of Bacterial Infections Studied in a Mouse-Model

Verena Hoerr1, Graciela Andonegui2, Lori Zbytnuik3, Paul Kubes3, Brent W. Winston3, Hans J. Vogel1

1Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada; 2Department of Critical Care Medicine, University of Calgary, Calgary, Alberta, Canada; 3Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada

The metabolic profiles of bacterial infections were studied on a mouse-model by high resolution 1H NMR spectroscopy. Serum samples of mice, infected with Staphylococcus aureus and Streptococcus pneumoniae showed significantly higher concentrations of leucine, phenylalanine, creatine and isoleucine compared to those of the healthy control group. Additionally malonate was elevated in the case of S. aureus infection while in S. pneumoniae infected mice the taurine level was increased. Analyzing the NMR spectral data by partial least squares discriminant analysis (PLS-DA) classification along bacterial infection was revealed with high accuracy.

14:30         4308.     Metabonomic Differentiation of Long-Term Dietary Intervention with NMR Spectroscopy of Human Urine Samples

Jingjing Xu1, Shuhui Cai1, Jiyang Dong1, Xuejun Li2, Zhong Chen1

1Department of Physics, Xiamen University, Xiamen, Fujian, China; 2Xiamen First Hospital, Xiamen, Fujian, China

The biochemical effects of omnivorous and vegetarian diets in human were investigated using NMR-based metabonomics on human urines. Different effects can be discriminated clearly according to the score plot of principle component analysis. Compared to the omnivorous group, urinary excretion of creatine, creatinine, TMAO, taurine, methylhistidine, glucose and DMA decreased following plant-based diet, with relatively increase in the level of 3-hydroxybutyrate, citrate and hippurate. All of the results show that different dietary components have great influences on the human metabolic phenotypes and the associations between food intake and metabolic pathway need further exploration.

15:00         4309.     Metabolism of Abnormal and Normal Colonic Mucosa of Patients with Ulcerative Colitis (UC) and Crohn’s Disease (CD): An In-Vitro Proton MRS Study

Uma Sharma1, Rajiv R. Singh1, Vineet Ahuja2, Govind K. Makharia2, Naranamangalam R. Jagannathan1

1Department of NMR and MRI Facility, All India Institute of Medcial Sciences, New Delhi, Delhi, India; 2Department of Gasteroenterology, All India Institute of Medcial Sciences, New Delhi, Delhi, India

Metabolism of normal and abnormal colonic mucosa of patients with ulcerative colitis (UC) and Crohn’s disease (CD) was investigated using in-vitro proton MRS. Significantly lower concentration of Lac, Cr/PCr ATP, GPC, Cho and mI was observed in normal and abnormal mucosa of UC and CD compared to controls indicating lower energy status. However, concentrations were similar for the normal and abnormal area of mucosa in patients. Loss of cellular energy may affect various energy dependent processes including electrolyte exchange, biosynthesis of macromolecules and detoxification. These metabolic abnormalities in normal mucosa indicate the progression of disease in UC and CD.

 


 
Spectroscopic Imaging Methods
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 77

14:00         4310.     High Spatial Resolution Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) in Human Brain at 3 Tesla Using 32-Channel RF Coil Array

Akio Ernesto Yoshimoto1, Andre van der Kouwe2, Arvind Caprihan3, Fa-Hsuan Lin2, Lawrence L. Wald2, Stefan Posse4

1Electrical and Computer Engineering, U. New Mexico, Albuquerque, NM, USA; 2MGH-HMS-MIT Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA; 3The MIND Research Network, Albuquerque, NM, USA; 4Neurology, U. New Mexico, Albuquerque, NM, USA

This MRSI study at 3T using a 32-channel head array coil demonstrates the feasibility of short TE (15 ms) mapping of singlet and J-coupled metabolites in human brain with a spatial resolution high enough to delineate cortical anatomical structures in metabolite images. MRSI data from a slice extending into lateral gray matter were acquired with Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) using 64x64 spatial matrix and 0.25 cc voxel size. Metabolite concentration estimates using LCModel fitting with relaxation and partial-volume correction were consistent with previous studies. This PEPSI methodology is suitable for investigating metabolic abnormalities in cortical brain lesions in neurological and psychiatric disease.

14:30         4311.     Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) in Human Breast

Chenguang Zhao1, Patrick Bolan2, Laurel Sillerud, Melanie Royce, Anne Marie Wallace, Steven Eberhardt, Robert Rosenberg, Philip Heintz, Lomo Lesley, Stefan Posse

1University of New Mexico, Albuquerque, NM, USA; 2University of Minnesota

This study describes the development of 2D and 3D

15:00         4312.     Short TE Volumetric Spiral 1H MR Spectroscopic Imaging of the Human Brain at 3T Using Semi-LASER

Mohamed Tachrount1,2, Laurent Lamalle3, Jan Warnking2, Christoph Segebarth2

1 U836 - Equipe 5, INSERM, Grenoble, France; 2GIN, Universite Joseph Fourier, Grenoble, France; 3IFR n 1, INSERM, Grenoble, France

Proton MR chemical shift imaging of brain metabolites can identify biomarkers relevant to healthy or metabolic cerebral metabolism. Here, short TE volumetric 1H Spiral Spectroscopic Imaging acquisition on the human brain in a total acquisition time compatible with clinical examination is demonstrated at 3T. Short TE acquisition allows detection of strongly J-coupled and short T2 metabolites. Volumetric acquisition allows better characterization over heterogeneous tissue. To reduce chemical shift displacement error and B1 heterogeneity effects, the semi-LASER approach is applied. Simultaneous spatial and spectral encodings with spiral waveforms reduces the minimum acquisition time.

15:30         4313.     High Field MR Spectroscopy of the Human Brain at Short TE and TR

Vincent Oltman Boer1, Jetse Sigiward van Gorp2, Peter R. Luijten1, Dennis Klomp1

1Radiology, UMC Utrecht, Utrecht, Netherlands; 2Wageningen University and Research Center, Wageningen, Netherlands

A method for high resolution (5x5x10mm3) spectroscopy at 7T is proposed. A high resolution 2D-CSI measurement is combined with broadband adiabatic water and fat suppression. Therefore SAR-demanding outer-volume suppression can be omitted. High quality spectra can be obtained at 1 second TR and 1.5ms acquisition delay (TE).

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 77

13:30         4314.     Comparison of TE-Averaged with Short TE Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) for Mapping Glutamate in Human Brain

Kaung-Ti Yung1, Shang-Yueh Tsai2, Fa-Hsuan Lin3,4, Pierre-Gilles Henry5, Akio Yoshimoto6, Stefan Posse7,8

1Neurology, University of New Mexico, Albuquerque, NM , USA; 2Electrical and Computer Engineering, National Taiwan University, Taipei, Taiwan, Taiwan; 3Athinoula A. Martinos Center for Biomedical Imaging, MGH-HMS-MIT, Charlestown, MA, USA; 4Radiology, Massachusetts General Hospital, Boston, MA, USA; 5Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA; 6Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA; 7Neurology, University of New Mexico, Albuquerque, NM, USA; 8Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM , USA

In this study we compare TE-averaged with short TE (15 ms) PEPSI data acquired in human brain at 3T, using identical voxel size (1 cc). Short TE data have higher SNR and Cramer-Rao lower bounds for Glu are lower compared to the TE-averaged data. The number of voxels above threshold for TE-averaged data is smaller than for short TE data. Short TE acquisition is advantageous for clinical studies for sensitivity reasons and due to the shorter measurement time. TE-averaged acquisition is complementary to short TE acquisition for identification of Glu albeit at lower spatial resolution.

14:00         4315.     Multi-Echo Acquisition Based J-Resolved Spectroscopic Imaging on a Whole-Body 3T Scanner

Gaurav Verma1, Saadallah Ramadan2, Nagarajan Rajakumar3, Scott Logan Lipnick3, Xiaoyu Sherry Liu3, Michael Albert Thomas3

1Bioengineering, Radiological Sciences, UCLA, Carson, CA, USA; 2Brigham & Women's Hospital, Radiology and Center for Clinical Spectroscopy, Boston, MA, USA; 3Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA

Spatial encoding has been integrated into a J-resolved spectroscopic sequence, resulting in a technique capable of acquiring 2D spectroscopic data over a 2D spatial array. A Multi-Echo based acquisition scheme was applied to the sequence to accelerate the acquisition rate. The viability of this sequence was demonstrated by acquiring five scans of a brain metabolite phantom with an 8-channel knee-array coil. The resulting spectra showed peaks due to a variety of metabolites at physiological concentrations and each produced a spherical spatial profile consistent with the shape of the brain phantom.

14:30         4316.     Echo-Planar Based Correlated Spectroscopic Imaging (EP-COSI): Implementation and Evaluation in Human Skeletal Muscle Using a 3T MRI Scanner and a 8-Channel Knee Coil.

Scott Logan Lipnick1, Saad Ramadan2, Guarav Verma, Michael Albert Thomas

1UCLA, Los Angeles, CA, USA; 2Harvard

The presented research details the implementation of Echo-Planar Correlation Spectroscopic Imaging (EP-COSI), which utilizes EPI readout, combined with phase encoding to obtain spatially resolved 2D Correlation Spectroscopy (COSY) spectral data sets. The 2D COSY spectra were obtained by iteratively acquiring 1D MRSI data sets with incrementally longer evolution times. The sequence was evaluated in the skeletal calf muscle of 5 healthy human subjects and detected water, unsaturated and saturate fatty acids, choline, and creatine. The results show sufficient spectral and spatial resolution to provide clinically relevant metabolic information, details for improving signal are also given.

15:00         4317.     31P Spectroscopic Imaging with GRAPPA

Rahul Srinivasa Raghavan1, Anshuman Panda2, Julien Valette3, Judy R. James2,4, Keith Heberlein5, Uwe Boettcher5, Pierre-Gille Henry6, Navin Bansal7, Ulrike Dydak2,4

1School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA; 2School of Health Sciences, Purdue University, West Lafayette, IN, USA; 3CEA-NeuroSpin, Gif-sur-Yvette, France; 4Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; 5Siemens Healthcare, Erlangen, Germany; 6Center for Magnetic Resonance Research,, University of Minnesota, USA; 7Department of Radiology, Indiana University, USA

Using a novel 8-channel phased-array dual-tuned 31P/1H coil the feasibility of using GRAPPA for accelerating 31P MRSI was tested. Single-slice 31P MRSI with 24x24 phase-encoding steps was acquired on a phantom, artificially undersampled and reconstructed with different GRAPPA acceleration factors. The reconstructed metabolite maps and spectra show acceptable quality and no aliasing artifacts, this showing that 31P MRSI can in principle be combined with parallel imaging. Whether 3D MRSI with large matrix sizes might be a candidate yielding enough SNR in vivo to be acquired with a single average and may benefit from GRAPPA acceleration is currently under investigation.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 77

13:30         4318.     Repeated Measures Performance of Whole-Brain Echo-Planar Spectroscopic Imaging at 4 Tesla

Andreas Ebel1,2, Norbert Schuff1,3

1Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA; 2Northern California Institute for Research and Education, San Francisco, CA, USA; 3Department of Radiology, University of California, San Francisco, CA, USA

While increased sensitivity provided by high magnetic fields can benefit volumetric whole-brain echo-planar spectroscopic imaging (3D EPSI) in several ways, the gain in measurement repeatability and reproducibility compared to EPSI performed at lower fields, i.e. 1.5T, has not been thoroughly investigated. Here, a test/retest study is presented for 3D EPSI of normal human brain at 4 T focusing on repeatability.

14:00         4319.     Accelerating TE-Averaged 2D Magnetic Resonance Spectroscopic Imaging Using Data-Sharing

Kuang-Ta Kuo1, Shang-Yueh Tsai2, Yi-Ru Lin1

1Eletronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 2Electrical Engineering, Chang Gung University, Taoyuan, Taiwan

Therefore, a method is introduced that the data-sharing property in radial acquisition by varying the TE at each radial line (or view) in a single acquisition. The results of the reconstructed spectra are expected to have similar TE-averaged property on the Glu resonance. This data-sharing property is further reduce the required scan time of TE-averaged technique.

14:30         4320.     In Vivo Fourier Shifted Two-Dimensional Zero-Quantum Coherence 1H NMR Spectroscopy of Glutamate and Glutamine

Sarah Rebecca Snyder1, Sebastian Schmitter1, Armin Nagel1, Peter Bachert1

1Dept. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

Previously, it has been shown that glutamate can be distinguished from glutamine when their zero-quantum coherence (ZQC) modulation frequencies as well as their chemical shift values are used as identification parameters in 2D spectra. However, acquisition times for such spectra exceeded four hours. We now show that by recording 2D spectra, which are undersampled along the ZCQ modulation frequency axis and then applying a Fourier Shift, glutamate can be distinguished from glutamine in 50 minutes. We demonstrate this on a healthy volunteer using a 3 Tesla whole-body MR tomograph and show that there is no loss in resolution.

15:00         4321.     Detection of Glutathione with High Precision in the Anterior Cingulate Using Short TE 1H MRS at 3T

Ralf Mekle1,2, Giulio Gambarota1, Tanja Teichmann3, Kim Q. Do3, Rolf Gruetter1,4

1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Federale de Lausanne, Lausanne, Vaud, Switzerland; 2Department of Radiology, University of Lausanne, Lausanne, Vaud, Switzerland; 3Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University - CHUV, Lausanne, Switzerland; 4Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Vaud, Switzerland

A neurochemical profile including the antioxidant glutathione (GSH) was measured with high precision using MRS for the application to schizophrenia. Localized proton spectra were acquired in the anterior cingulate for N=4 volunteers using the spin echo full intensity acquired localized (SPECIAL) MRS technique. Scans were performed on a clinical platform using a TEM volume coil at 3T. Results yielded excellent data quality and detection of GSH with mean Cramer-Rao lower bound (CRLB) of 9%. Fourteen additional metabolites were quantified with CRLBs below 20%. Detection precision was sufficiently high for treatment monitoring of schizophrenic patients after administration of therapeutic drugs.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 77

13:30         4322.     Correction of Frequency Drifts Induced by Gradient Heating in 1H Spectra Using Interleaved Reference Spectroscopy

Thomas Lange1, Maxim Zaitsev1, Martin Buechert1

1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany

Long MRI measurements utilizing high gradient duty cycle can heat up the passive shim elements of the MR system giving rise to frequency drifts in subsequent MRS experiments. The interleaved reference scan (IRS) method is used for correcting these frequency drifts in 1H spectra in vitro and in vivo. IRS implies the acquisition of an additional water reference spectrum after every spectral average. The line widths of the spectral resonances can be largely reduced using the reference signal for phase correction. This may improve peak resolution and SNR considerably, allowing a more valid data analysis in clinical studies.

14:00         4323.     VERSE Implementation for STEAM at 7 T

Oleksandr Khorkhordin1, Frank Godenschweger1, Kai Zhong1, Oliver Speck1

1Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany

RF inhomogeneity at 7 T creates problems for MRS due to the limited available transmitter voltage. Standard spectroscopic sequences such as STEAM or PRESS require short and thus high bandwidth 90° or 180° pulses for selective volume excitation in locations with low B1. In this study, VERSE was implemented in a STEAM sequence to reduce the peak voltage requirement for the excitation pulses. The modified sequence was tested in both phantom and in vivo studies and the results showed clear improvement of the spectra compared to 3T.

14:30         4324.     Bo Anchored Spatial Excitation for Spectroscopic Imaging Under Field Inhomogeneity

Arnaud Guidon1, Allen W. Song1

1Brain Imaging and Analysis Center, Duke University, Durham, NC, USA

In this work, we present a new method aimed at achieving robust spectroscopic metabolite imaging in the presence of inhomogeneous magnetic fields. This technique is based on a new excitation strategy termed Bo anchor spatial excitation (BASE), which could take advantage of the recent advances in parallel transmission to achieve a region-specific, frequency-matched excitation. In particular, we show that BASE can help recover spectral resolution in regions where field heterogeneity would otherwise lead to severe off-resonance and dispersion effects. We anticipate that this method will find broad applications leading to more effective whole-brain spectroscopic imaging in vivo.

15:00         4325.     Stereoscopic Acquisition and Display of MR Spectroscopic Images

Richard A. Edden1, Paul A. Warren2, Christopher John Evans2

1Schools of Chemistry and Biosciences, Cardiff University, Cardiff, Wales, UK; 2CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, UK

Stereoscopic presentation of image data allows additional information content to be encoded in the depth dimension. We present a method for employing the chemical shift displacement artefact to achieve this and present phantom and in vivo data demonstrating the effect.

 


 
Metabolite Quantitation Methodology
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 78

14:00         4326.     J-Resolved 1H Spectroscopic Imaging of Human Brain

Atilla Gonenc1, Sulaiman Sheriff1, Varanavasi Govind1, Andrew A. Maudsley1

1Department of Radiology, University of Miami, Miami, FL, USA

Two-dimensional J-resolved proton MRSI has been implemented at 3T and results for imaging of glutamate, glutamine, and myo-Inositol in human brain are presented. Data has been analyzed to determine the relative grey-matter and white-matter concentrations and differences with age and gender, as well as the T2 relaxation times for all detected metabolites.

14:30         4327.     Breast Tissue Classifications by CART Analysis of Localized 2D COSY

Xiaoyu Liu1, Scott lipnick1, James Sayre1, Shida Banakar1, Nanette Debruhl1, Michael Albert Thomas1

1Radiology, UCLA, David Geffen School of Medicine, Los Angeles, CA, USA

Magnetic Resonance Spectroscopy (MRS) allows noninvasive measurements of the concentration of metabolites in human breast in vivo. Two-dimensional (2D) MRS has improved resolution than one-dimensional (1D) MRS due to the additional J-coupling information in the second dimension. 2D COSY of breast tissues showed several metabolite and lipid ratios that are significantly different between different breast tissues. In this study we use classification and regression tree (CART) analysis for classification of four different breast tissues (malignant tumor, benign tumor, healthy fatty and healthy glandular tissues) based on the metabolite ratios from 2D COSY of breast tissues in vivo.

15:00         4328.     Two-Dimensional Fitting for in Vivo NMR Spectra Quantification

Antonio Napolitano1, D Auer1, W Koeckenberger2

1Department of Academic Radiology, University of Nottingham, Nottingham, UK; 2SPMMRC, School of Physics and Astronomy, University of Nottingham, Nottingham, UK

The present work is based on the development and implementation of a software package that makes it possible to determinate both the absolute concentrations and the T2 values in a brain metabolite phantom. This method, implemented using MATLAB, has the advantage of computing the T2 values and performing an automatic correction of the concentrations by time relaxation. The output is then an absolute quantification determined by water reference and an estimation of spin-spin relaxation times of resonances of interest for in vivo spectroscopy.

15:30         4329.     The Linear Relationship Between Cross-Peak Volume and Concentration of Metabolites in 2D Localized MR Spectroscopy

Hui Liu1, Jeon-Hor Chen1,2, Hyeon-Man Baek1, Mark J. Hamamura1, Seung-Hoon Ha1, Min-Ying Lydia Su1, Orhan Nalcioglu1

1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Department of Radiology, China Medical University, Taichung, Taiwan

The linear relationship between the cross-peak volume and metabolite concentration measured by two-dimensional localized MR Spectroscopy was investigated. Phantom solutions containing five different concentrations (6, 10, 20, 40, 50 mM) of polyamine spermine, and another set of composite phantoms containing polyamine spermine, choline, and creatine with 20, 40, 60 mM were studied. The 2D L-COSY and 2D L-JPRESS were used to acquire the 2D spectra. The linear correlation coefficient between integrated cross-peak volume and metabolite concentration was between 0.97~0.99. Using the composite phantom we also show that the diagonal peak of creatine can be used as an internal reference.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 78

13:30         4330.     Measurements of IMCL in Tibialis Anterior in Normal and Ob/ob Mice Using a Cryogenic Surface Coil at 9.4 T

Qiong Ye1, Christof Baltes1, Thomas Mueggler1, Markus Rudin1,2

1D-ITET, Institute for Biomedical Engineering, Zürich, Switzerland; 2Institute for Pharmacology and Toxicology, Zürich, Switzerland

The non-invasive investigation of intromyocellular lipid (IMCL) with proton MR spectroscopy (1H MRS) in humans and rodents has been studied widely. In this work, the reproducibility of single voxel 1H MRS to detect IMCL levels in the tibialis anterior (TA) muscle in mice under different feeding conditions and model lines is evaluated using a cryogenic transceiver RF coil. From the results, both diet conditions and model lines have effect on IMCL levels. This study achieves high quality spectra obtained from volumes of 3.2mm3 and less with reliable reproducibility.

14:00         4331.     How Much Fat Is Under the Water Peak in Liver Fat MR Spectroscopy?

Michael Simca Middleton1, Gavin Hamilton1, Mark Bydder1, Claude B. Sirlin1

1Radiology, UCSD School of Medicine, San Diego, CA, USA

Accurate MRS liver fat quantitation requires determination of signal from fat peaks that are near or under the water peak. As reported in the literature, the amount of fat in those peaks is determined by fatty acid chain length, number of carbon double bonds, and number of carbon double bonds separated by a single -CH2- group. We validated that we could predict, from the corn oil 0-3 ppm spectrum, the amount of fat that would be under the water peak, and applied that method for in-vivo human liver MRS data to estimate the amount of fat under the water peak.

14:30         4332.     Estimation of Intrinsic Relaxation Parameters of Human Brain Metabolites in Vivo

Silvia Mangia1, Michael Garwood1, Pierre-Gilles Henry1, Kamil Ugurbil1, Shalom Michaeli1

1Radiology, University of Minnesota, Minneapolis, MN, USA

In the present study we estimated the intrinsic relaxation parameters characterizing the dynamics of human brain metabolites (N-Acetylaspartate, NAA, and total-Creatine, t-Cr) from in vivo adiabatic relaxation measurements. The performed simulations relied on few a-priori assumptions regarding known properties of NAA and t-Cr, and were based on the theoretical description of several relaxation channels in the weak field approximation, namely: dipolar interactions, isochronous exchange, anisochronous exchange, and diffusion. Since the intrinsic relaxation parameters are supposed to be sensitive to different functional states, this approach holds great potential to quantitatively assess metabolic processes of interest for biomedical research.

15:00         4333.     Automatic Detection of Lipid Peaks in MR Spectroscopic Image Data Using Artificial Neural Networks

Balasrinivasa R. Sajja1, Himanshu Bhat2, Michael D. Boska1, Ponnada A. Narayana3

1Department of Radiology, Univ. of Nebraska Medical Center, Omaha, NE, USA; 2Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA; 3Department of Diagnostic and Interventional Imaging, Univ. of Texas Medical School, Houston, TX, USA

Presence of lipid in brain may represent active de- or re-myelination in multiple sclerosis. Manual examination of each voxel for lipid peak in MRSI data is tedious and this becomes acute in multicenter clinical trials where large data need to be analyzed. In this study, we present a rapid and robust method based on artificial neural networks for automatic identification of lipid peaks in MRSI data.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 78

13:30         4334.     Study of the Characteristics of Normal Breast Tissue During Various Phases of Menstrual Cycle by in Vivo Volume Localized Proton MR Spectroscopy (MRS)

Naranamangalam R. Jagannathan1, Mahesh Kumar1, Uma Sharma1, Rani Gupta Sah1

1Department of NMR and MRI Facility, All India Institute of Medcial Sciences, New Delhi, Delhi, India

In vivo proton MRS from various regions of normal breast of 24 volunteers revealed cyclic variation in the W-F value of para-areolar region during menstrual cycle. In para-areolar region, W-F value was 0.96 ± 0.5 during proliferative phase and reduced to 0.47 ± 0.18 and 0.40 ± 0.29 during follicular and luteal phases. It increased to 0.77 ± 0.6 and to 0.87 ± 0.7 during secretory and menstrual phases. No change was observed for upper and lower quadrants. Any assessment of breast disease using W-F ratio needs careful consideration of location and effect of menstrual related variation in tissue characteristics.

14:00         4335.     Reduction of Endorectal Surface Coil Artifact in 1H Spectroscopic MRI of Prostate Cancer

Galen Durant Reed1, John Kurhanewicz1, Daniel B. Vigneron1, Susan M. Noworolski1

1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA

Automated detection of prostate cancer using the metabolite peak integrals of MRSI data is notoriously difficult due to the spatial inhomogeneity of the endorectal surface coil. A semi-automatic correction algorithm which normalizes MRSI data to the coil’s analytic field map was applied to three phantoms’ and 18 prostate cancer patients’ 3T MRSI data. Spectral peaks showed increased spatial homogeneity: 39% and 30% for suppressed water and citrate (phantoms) and 30% for suppressed water (patients). Additionally, maps of coil-corrected choline integrals showed potential in identifying anterior prostate carcinomas which were not clearly identifiable on un-normalized metabolite maps or metabolite ratio maps.

14:30         4336.     Quantitative Magic Angle Spinning Detection of Deuteration in Small Biopsies of Rat Brain

Maria Rosa Fayos Carrio1, Valeria Righi2, Adele Mucci2, Luisa Schenetti2, Sebastián Cerdán1

1IIB, CSIC, Madrid, Spain; 2Università di Modena, Italy

Deuterium turnover experiments of 13C labelled metabolites provide a novel tool to investigate metabolite turnover under the faster timescale conditions of hydrogen-deuterium exchange. An important magnitude is the fractional deuteration of specific hydrogen positions of the 13C labelled isotopomers. To this end, relatively large tissue biopsies were previously needed to prepare the extracts required for the High Resolution 13C, 1H or 2H NMR analysis. In this report we describe a variety of 1D (1H, 2H) and 2D (1H-2H, 1H-13C) methods allowing the determination of fractional metabolite deuteration in specific proton sites using 1H, 2H and 13C HR MAS spectroscopy.

15:00         4337.     A Comparison Between Simulated and Experimental Basis Sets for the Analysis of Short-Echo In-Vivo MRS Data at 1.5T

Martin Wilson1,2, Nigel P. Davies1,2, Yu Sun2,3, Kal Natarajan2, Theo N. Arvanitis2,3, Andrew C. Peet1,2

1Cancer Sciences, University of Birmingham, Birmingham, West Midlands, UK; 2Oncology, Birmingham Childrens Hospital Foundation Trust, Birmingham, West Midlands, UK; 3School of Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, West Midlands, UK

The use of a simulated basis set for the analysis of 1H short-echo MRS data offers a number of advantages over an experimental basis set. One main advantage is that simulated basis sets can be easily regenerated for a particular echo-time or field strength without requiring hours of scanner time. In this study a comparison is performed between the metabolite quantities estimated by LCModel using simulated and experimental basis. A good correlation is seen between both methods suggesting that little bias is introduced by using a simulated basis set.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 78

13:30         4338.     Absolute Quantification of 1H Magnetic Resonance Spectroscopy of Human Brain Using QMRI

Anders Tisell1,2, Olof Dahlqvist Leinhard1,2, Marcel Warntjes1,2, Janne West1,2, Peter Lundberg1,2

1Department of medical and health sciences, Division of radiological sciences, University of Linkoping, Linköping, Sweden; 2Center for Medical Image science and Visualization (CMIV), University of Linkoping, Linkoping, Sweden

In this work a method for absolute quantification of proton MRS is presented. The method are base on using the internal water as an reference an Quantitative MRI for absolute quantification of the internal water. Since measurements of the internal water signal is done automatically before any proton MRS measurement and the the qMRI volume only have to cover the voxel the method becomes very user independent

14:00         4339.     Comparing Methods for Absolute Quantification of Brain Metabolites in Grey and White Matter

Claudia Testa1, Emil Malucelli1, David Neil Manners1, Caterina Tonon1, Raffaele Lodi1, Bruno Barbiroli1, Stefano Iotti1

1University of Bologna, Bologna, Italy

We tested two methods of absolute quantification for brain metabolite concentrations in grey and white matter. Data were analyzed by LCModel. The individual protocol (IP) determines the T2 of Cho, Cr and NAA by fitting the mono-exponential decay of their signal and the bi-exponential decay of water at different echo times to calculate concentrations. The mean protocol (MP) determines concentrations at TE=35 ms using the mean value obtained from the T2 data set of the corresponding metabolite. Statistical analysis shows that the use of either IP or MP does not significantly affect concentrations values.

14:30         4340.     jMRUI Version 4 : A Plug-In Platform

Dan Stefan1, Adrian Andrasecu1, Emil Popa2, Andrii Lazariev2, Oliver Strbak3, Zenon Starcuk3, Miquel Cabanas4, Dirk Ormondt5, Danielle Graveron-Demilly2

1Alter Systems, Lyon, France; 2Laboratoire Creatis-LRMN; CNRS UMR 5220; INSERM U630; INSA de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France; 3Department of Magnetic Resonance & Bioinformatics, Institute of Scientific Instruments of the ASCR, Brno, Czech Republic; 4Servei de Ressonancia Magnetica Nuclear,, Universitat Autonoma de Barcelona, Barcelona, Spain; 5Applied Physics, Delft University of Technology, Delft, Netherlands

The software package jMRUI with Java-based Graphical User Interface enables user-friendly time-domain analysis of Magnetic Resonance Spectroscopy (MRS) and Spectroscopic Imaging (MRSI), and HRMAS-NMR signals. In addition, it offers a quantum-mechanical signal simulator NMR-SCOPE. The version 3.x has been distributed in 1200 research groups or hospitals world-wide. The new version 4.x is a plug-in platform enabling the users to add their own algorithms. Moreover, it offers new functionalities compared to the versions 3.x.

15:00         4341.     In Vitro Spectroscopic Method Under Clinical Conditions for in Vivo Mannitol Detection

Gabriela Hossu1, François Kauffmann2, Nicolas Courouble1, Caroline Henry3, Mikael Jokic4, Antoine Coquerel5, Pierre Denise6, Jean-Marc Constans1,7

1MRI Unit, Caen University Hospital, Caen, Normandy, France; 2LMNO CNRS UMR 6139, Caen University, Caen, Normandy, France; 3Hematology Service, Caen University Hospital, Caen, Normandy, France; 4Infant Surgery, Caen University Hospital, Caen, Normandy, France; 5Pharmacology, Caen University Hospital, Caen, Normandy, France; 6Physiology, Caen University Hospital, Caen, Normandy, France; 7CERVOxy and UMR6232 CI-NAPS , Cyceron, Caen, Normandy, France

Using prior knowledge for in vitro studies performed under the same conditions as patient examinations may improve identification of lesser-known components such as neurogenesis peaks, apoptosis biomarkers or medications. We studied in vitro measurements acquired under in vivo conditions using a test object composed of three separate compartments for Mannitol drug and using 1% TMS in CDCl3 and Choline as internal references. We propose a new approach to analyzing and validating reproducibility of spectroscopic patterns. Consequently, in vivo identification of Mannitol accumulation in human brain pathologies can be measured, for the first time, with a higher level of precision.

 


 
MRS Methodology, MR Elastrography, Non-Proton MRI
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 79

14:00         4342.     Solid-State NMR Adiabatic TOBSY Provides Enhanced Sensitivity for Multidimensional High-Resolution Magic-Angle-Spinning H1 MR Spectroscopy in Burn Trauma

Valeria Righi1, Ovidiu C. Andronesi1, Dionyssios Mintzopoulos1, A. Aria Tzika1

1NMR Surgical Laboratory, MGH & Shriners Hospitals, Harvard Medical School, Boston, MA, USA

We propose a solid-state NMR method that maximizes the advantages of high-resolution magic-angle-spinning (HRMAS) applied to intact biopsies when compared to more conventional liquid-state NMR approaches. Numerical simulations and experimental results on skeletal muscle specimens from burn trauma are presented. Experimentally, it is shown that an optimized adiabatic TOBSY (TOtal through Bond correlation SpectroscopY) solid-state NMR pulse sequence for two-dimensional 1H-1H homonuclear scalar-coupling longitudinal isotropic mixing provides a 50-60% improvement in signal-to-noise ratio relative to its liquid-state analogue TOCSY (TOtal Correlation SpectroscopY). We demonstrate a concept for HRMAS metabolic profiling of burn trauma, from biopsies requiring reduced sample degradation for further genomic analysis.

14:30         4343.     Determinants of Magnetization Transfer Efficiency in Tissue and Cells

Jin-Hong Chen1, Rachael O'Connor1, Penelope DeCarolis1, Samuel Singer1

1Memorial Sloan-Kettering Cancer Center, New York, NY, USA

Magnetization transfer (MT) between water and cell lattice protons is an important contrast mechanism and a major determinant of the tissue water relaxation time. MT involves an interaction network that includes cross relaxation, spin-diffusion and chemical exchange. This study identifies the determinants of MT efficiency between water and cell lattice protons and shows that labile protons play a critical role in MT between water and cell lattice. Saturation of the cell lattice determines the degree of magnetization reduction of water due to MT and is dependent on the relative intensity of the irradiation pulse and residual dipolar coupling in tissue.

15:00         4344.     Detection of Glycine Residue of Glutathione in Vivo

Lana G. Kaiser1, Susanne Mueller1, Gerald B. Matson2, Karl Young1

1Department of Radiology, UC San Francisco, San Francisco, CA, USA; 2Department of Pharmaceutical Chemistry, UC San Francisco, San Francisco, CA, USA

Glutathione (GSH) is a powerful antioxidant in the human brain. Previous 1H MRS methods focused mainly on the editing of the cysteine moiety of the GSH to overcome spectral overlap with creatine singlet at 3.0 ppm. The proposed method focuses on the glycine residue of GSH, which is overlapped by glutamate and glutamine (Glx) under physiological pH and temperature at 3.75 ppm. The proposed scheme utilizes J-difference editing to quantify Glx contribution to separate it from a target resonance of glycine moiety of GSH. Resultant signal to noise ratio of the GSH signal is shown to yield a significant improvement compared to previously used methods.

15:30         4345.     Fat Composition Assessment by 1H and 13C Spectroscopy in Mice

Marina Benito1, Sonia Fernández2, Paula Montesinos1, Juan Jose Vaquero1, Cristina Chavarrias1, Manuel Desco1,3

1Medicina y Cirugía Experimental, Hospital General Universitario Gregorio Marañón, Madrid, Spain; 2Dpto. Bioquimica y Biologia Molecular II, Universidad Complutense de Madrid, Madrid, Spain; 3Centro de investigación en red en salud mental (CIBERSAM), Madrid, Spain

This study proposes a straightforward method to quantitatively analyze body lipid content and fatty acid composition (saturation) by means of 1H and 13C spectroscopy. Results have been tested with 24 mice of wild type (12) and genetically obese diabetic (12), scanned at 5, 9, 18 months of age. 1H and proton-decoupled 13C spectra were acquired in vivo from epididymal fat. Clear differences have been found between both types of animals. The proposed approach has proven to be valuable to non-invasively characterize lipid composition, and is suitable for research in obesity-related disorders, such as insulin resistance and type-2 diabetes.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 79

13:30         4346.     MR Elastography Sampling Requirements: Preliminary Investigations

Kevin John Glaser1, Armando Manduca1, Richard Lorne Ehman1

1Radiology, Mayo Clinic, Rochester, MN, USA

MR elastography (MRE) has become a clinically valuable technique for applications such as breast and liver imaging. For MRE to continue to be used in clinical practice, the imaging times must be kept short enough for patient compliance. One way to reduce imaging times is to lower the resolution of the acquisition. However, because of the phase-based nature of MRE, MRE data cannot always be undersampled the way that magnitude-based MRI can. This work explores a model for the k-space properties of MRE data to investigate the relationship between undersampling the data and the quality of the elastograms.

14:00         4347.     Data Reduction Analysis for Brain MR Elastography

Matthew C. Murphy1, Kevin J. Glaser2, Armando Manduca2, Joel P. Felmlee2, Richard L. Ehman2

1Mayo Clinic College of Medicine, Rochester, MN, USA; 2Mayo Clinic College of Medicine, Rochester, Minnesota, USA

MR Elastography of the brain is being investigated as a technique capable of diagnosing currently undetectable diseases. To ensure patient comfort, acquisition time must be minimized, particularly the time of active vibration of the head. This work aims to determine how much k-space data must be collected to reliably estimate the stiffness of brain tissue. Methods of data reduction investigated here include replacement with either k-space data from an equivalent acquisition without any vibration or simply zeros.

14:30         4348.     Analysis of the Capability of Transurethral MR Elastography to Detect and Quantify Localized Stiffness Changes for Prostate Imaging

Arvin Arani1,2, Rajiv Chopra1,2, Donald Plewes1,2

1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Problem: The objective of this study was to evaluate the capability of transurethral MR elastography to detect and quantify localized stiffness changes for prostate cancer imaging.

15:00         4349.     Simulation of Wave Fields Observed in Brain MR Elastography by 3D Finite Element Analysis

Uwe Hamhaber1, Dieter Klatt2, Sebastian Papazoglou2, Ingolf Sack2, Jürgen Braun1

1Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany; 2Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany

Data reported for the shear modulus of brain tissue determined using MR elastography varies substantially. Among other reasons these variations may caused by the not yet fully understood mechanisms which are responsible for the transfer externally forced head vibrations into propagating shear waves inside the brain. For this reason two different mechanical excitation modes which are commonly applied to generate mechanical shear waves inside the brain tissue were simulated by a 3D finite element analysis. Results show a good overall agreement between simulated and measured wave field patterns.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 79

13:30         4350.     Computer Simulation of Breast Compression Based on Segmented Breast and Fibroglandular Tissues on MRI

Tzu-Ching Shih1,2, Dongxu Liu3, Jeon-Hor Chen1,4, Lizhi Sun3, Ke Nie1, Huiming Yin5, Daniel Chang1, Orhan Nalcioglu1, Min-Ying Lydia Su1

1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Department of Medical Radiology Technology, China Medical University, Taichung, Taiwan; 3Department of Civil and Environmental Engineering, University of California, Irvine, CA, USA; 4Department of Radiology, China Medical University Hospital, Taiwan; 5Department of Civil Engineering and Engineering Mechanics, Columbia University, New York, NY, USA

We developed a 3D modeling analysis to investigate the impact of breast compression on mammographic density. MRI provides 3D information of breast and fibroglandular tissue for creating a 3D model. The volume mesh was created using the ANSYS ICEM CFD software, then the MSC Marc software was used to simulate the breast compression deformation. The results showed that the density variation between 40% to 60% compression level was around 8% on CC view, and 12% on MLO view. The simulation model can be applied to gain more in-depth understanding about the dependence of mammographic density on the potential technical factors.

14:00         4351.     Magnetic Resonance Poroelastography of the Feline Brain

Phillip Robert Perrinez1, S. Scott Lollis2, Francis E. Kennedy1, John B. Weaver1,3, Ketih D. Paulsen1,4

1Thayer School of Engineering, Hanover, NH, USA; 2Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA; 3Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA; 4Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA

Magnetic resonance poroelastography (MRPE) has been developed as an alternative to linearly elastic MR elastography techniques. This approach models tissue comprised of two distinct phases; a porous elastic solid and penetrating fluid. MRE image data were acquired for a series of feline subjects at varying degrees of hydrocephaly resulting from induced ventricular obstruction. Estimates of the time-harmonic pore-pressure distribution across the feline brain were computed, the magnitude of which was found to be associated with ventricular dilatation - a surrogate for increased intracranial pressure. The average whole-brain shear modulus was not found to vary significantly with hydrostatic pressure.

14:30         4352.     MRI-Based Noninvasive Measurement of Intracranial Compliance from the Relationship Between Transcranial Blood and CSF Flows: Modeling Vs Direct Approach

Rong-Wen Tain1, Noam Alperin1

1University of Illinois, Chicago, IL, USA

Intracranial compliance (ICC) determines the ability of the intracranial space to accommodate increase in volume (e.g., brain swelling) without a large increase in intracranial pressure. A recently proposed method derives ICC from the ratio of the intracranial volume and pressure changes that occur naturally with each heart beat. In this study, an RLC circuit model was used to quantify the effect of changes in ICC on the amplitude and phase of the CSF flow. We observed that changes in ICC predominantly affected the amplitude and less so the phase. This explains why phase based techniques are less sensitive than amplitude based approach.

15:00         4353.     Evaluation of Intracavitary Pneumatic Actuators for Prostate MR Elastography

Rajiv Chopra1,2, Ali Punjani1, Arvin Arani1,2, Anthony Chau1, Donald Plewes1,2

1Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

The purpose of this study was to evaluate intrcavitary pneumatic actuators for use in prostate MR elastography. Prototype transrectal actuators were built and characterised using a scanning laser vibrometer and MRE experiments in a gel phantom. Vibrometer characterization revealed a resonance in the frequency response of the actuators, and a different performance in air and water. The actuators produced shear wave propagation at 390 and 780 Hz that was visualized with MRE in the gel, and accurate estimates of the underlying stiffness of the material were obtained. This method has promise for prostate MR elastography.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 79

13:30         4354.     Triple-Quantum-Filtered Sodium MRI of the Human Brain at 4.7T

Adrian Tsang1, Rob Stobbe1, Christian Beaulieu1

1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

Triple-quantum-filtered (TQF) MRI for imaging microscopic ordered tissue sodium, presumably mainly intra-cellular, is challenging due to the limited signal-to-noise ratio and has only ever been applied once to in vivo human brain at 3T. The goal of our study is to improve the image quality of the triple quantum filtered sodium brain images by utilizing modified 3D twisted projection imaging with the higher static magnetic field strength of 4.7T. We show that TQF sodium MRI is achievable in a reasonable 11 min with adequate resolution to delineate brain structures such as the ventricles.

14:00         4355.     Investigation of a Non-Alcoholic Fatty Liver Disease Model Using 23Na, 1H and 31P MR Techniques

Paige Hopewell1,2, Navin Bansal1

1Department of Radiology, Indiana University, Indianapolis, IN, USA; 2Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA

Multinuclear MR techniques were used to examine a non-alcoholic fatty liver disease model, rats fed a methionine- and choline-deficient diet. The use of frequency-suppressed 1H MRI was compared to localized 1H MRS. Although the fat-to-water SI did not directly correlate temporally with the dominant lipid peak, (CH2)n, the changes in other lipid peaks showed that stage progression is not merely a change in (CH2)n/H2O, but changes in different lipid moieties. Alterations in the transmembrane sodium gradient and fibrosis-associated macromolecule deposition were examined using single quantum and triple quantum-filtered 23Na MRI, with shift reagent-aided 23Na and 31P techniques in agreement.

14:30         4356.     Evaluation of Severe Anemia by Quantitatively Measuring Multi-Organ Oxygen Using  19 F MRI in a Rat Model

Siyuan Liu1,2, Sameer J. Shah2, Lisa J. Wilmes1, Vikram Kodibagkar3, Michael F. Wendland1, Nola Hylton1, Harriet W. Hopf4, Ralph P. Mason3, Mark D. Rollins2

1Radiology, University of California, San Francisco, San Francisco, CA, USA; 2Anesthesia, University of California, San Francisco, San Francisco, CA, USA; 3Radiology, University of Texas at Southwestern, Dallas, TX, USA; 4Anesthesia, University of Utah, Salt Lake City, UT, USA

Supplemental oxygen is often given to anemic patients, yet the changes in individual organ pO2 from anemia and hyperoxia are poorly quantified. We used 19F MRI to measure the effects of severe anemia and hyperoxia on individual rat organs using a 7T system, 19F/1H volume coil, and FREDOM sequence. The pO2 in all organs examined decreased a small, quantifiable amount with severe isovolemic anemia, and increased above baseline values with inspiration of 100% oxygen. Preliminary findings suggest supplemental oxygen effectively increases organ oxygenation during anemia, and the 19F MRI method is valuable in quantifying the effectiveness of various resuscitation interventions.

15:00         4357.     Single-Point 19F Imaging of Fluorinated Drugs Injected Into the Eye for the Treatment of Macular Degeneration

Gerrit Hendrik van de Maat1, Annette van der Toorn1, B A. Zonnenberg2, Peter R. Seevinck1, Wouter Bult2, J Frank Nijsen2, Hendrik de Leeuw1, Chris J. Bakker1,3

1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Department of Nuclear Medicine, University Medical Center Utrecht, Utrecht, Netherlands; 3Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands

The potential of 19F MRI using Single-point imaging (SPI) to monitor the distribution of fluorinated drugs in the eye for treatment of macular degeneration was explored. An ex vivo study of enucleated bovine eyes injected with Perfluorooctylbromide (PFOB) was performed using a SPI technique. Since signal is integrated across the entire spectrum, SPI provides high sensitivity and immunity to chemical shift artifacts which was clearly shown from the results. It also averts the need of fluorine compounds resonating at a single frequency. Therefore 19F single-point imaging promises to provide a useful way of monitoring fluorinated drugs injected into the eye.

 


 
Microscopy, Perfusion, ESR
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 80

14:00         4358.     A SNR Comparison Study of Multiple Mouse Embryo MRI

Xiaoli Zhang1,2, Jurgen E. Schneider3, Angela Franklyn3, R Mark Henkelman1,2

1Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada; 3Department of Cardiovascular Medicine, University of Oxford, Oxford, UK

The purpose of this study was to compare SNR between two high-throughput multiple mouse embryo MRI methods:(a) use a single RF coil to image multiple embryos in one tube compared to (b) multiple embryos each is scanned concurrently with closely-fit RF coil.

14:30         4359.     Structural Characterization of Single Calcium Alginate Beads by 2.35 T MRI and MRS Methods

Matteo Bascelli1, Antonietta Fracassi2, Leonardo Adamo Pajewski1, Antonello Sotgiu2, Marcello Alecci2

1Department CICM, University of L'Aquila, L'Aquila, Italy; 2Department SdS, University of L'Aquila, L'Aquila, Italy

Here we report the combined use of MRS and MRI at 2.35 T to study the microscopic structure of single alginate gel beads. We show that beads of about 3 mm in diameter present T2 map heterogeneity that can be attributed to polymer concentration gradients.

15:00         4360.     Metabolic Spatial Heterogeneities in Brain Tumours Biopsies by NMR Microscopy

Bernardo Celda1,2, MCarmen Martinez-Bisbal2, Beatriz Martinez-Granados1, Vicent Esteve2

1Physical Chemistry, University of Valencia, Burjassot, Valencia, Spain; 2Physical Chemistry-UVEG, CIBER-BBN, Burjassot, Valencia, Spain

HR-MAS metabolic profiles in biopsies have been useful for classifying and subtyping brain tumours. However, HR-MAS can exclusively provide the average metabolic profile of the biopsy studied. SV and MRSI techniques by NMR microscopy have been used for obtaining biochemical average and spatial distribution in very heterogeneous lesions as brain tumours. Particular attention has been focussed in high grade gliomas. Excellent resolution and S/N of the metabolic profiles from SV and MRSI spectra were obtained. A good correlation between histology and detailed spatial metabolic profiles and between HR-MAS and global MRSI NMR microscopy spectra has been found.

15:30         4361.     MR Microscopy in Studying the Development of the Chick Inner Ear

Jerod Rasmussen1, Vinod Kaimal2, Scott K. Holland3, Jaye Ward3, Daniel Choo3

1BioInformatics Research Network, UC Irvine, Irvine, CA, USA; 2Imaging, MIR Preclinical Services, Ann Arbor, MI, USA; 3Cincinnati Children's Hospital, Cincinnati, OH, USA

Advancing our understanding of inner ear morphogenesis is essential to comprehension of and strategies for managing congenital hearing loss. This study investigates the feasibility of visualizing development through embryological time points using MR microscopy as a non-invasive and non-terminal imaging modality. High resolution 3D fast spin echo and steady state imaging sequences were utilized to investigate the spatial and temporal resolution limits respectively. High spatial resolution images were obtained using deceased in ovo embryos at varying embryonic stages to simulate a longitudinal study. A single embryo was imaged to examine range of motion at high temporal resolution in vivo.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 80

13:30         4362.     Uncertainty in VFA T1 Mapping with Multiple Flip Angles

Matthias Christian Schabel1, Glen R. Morrell1

1Radiology, University of Utah, Salt Lake City, UT, USA

A rigorous lower bound to T1 uncertainty in dual flip angle VFA measurements is derived from a propagation of errors analysis of the signal equation. Monte Carlo simulations suggest that this lower bound also applies to VFA measurements made with 3 or more flip angles.

14:00         4363.     Improved Quantification of Pharmacokinetic Parameters at 3 Tesla Considering B1 Inhomogeneities

Robert Merwa1, Gernot Reishofer2, Thorsten Feiweier3, Karin Kapp4, Franz Ebner2, Rudolf Stollberger1

1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Department of Radiology, Medical University of Graz, Graz, Austria; 3MED MR PLM AW Neurology, Siemens AG Healthcare Sector, Erlangen, Germany; 4Department of Radiation Therapy, Medical University of Graz, Graz, Austria

The determination of kinetic parameters depends strongly on the inhomogenities of the RF-field. Due to the magnitude of these inhomogenities the values for the AIF and tissue concentrations are widespread which lead to an overestimation or underestimation of Ktrans and Ve. An essential improvement can be achieved if the dynamic data are corrected accordingly. The absolute difference of Ktrans and Ve obtained with the AIF in two comparable arteries can be improved by a factor up to 33 when using the correction procedure. Also the coefficient of variation of the kinetic parameters could be improved.

14:30         4364.     Using DCE-MRI as a Method for Sequential in Vivo Evaluation of New Angiogenesis After Sinus Lift Augmentation

Ulrike Fasol1, Dagmar Fisch1, Juergen Hennig1, Moritz Palmowski2, Michael Vogeler3, Rainer Schmelzeisen3, Ralf Gutwald3, Sebastian Sauerbier3

1MR Development and Application Center, University Hospital Freiburg, Freiburg, Germany; 2Dep. of Diagnostic Radiology and Institute of Experimental Molecular Imaging, RWTH-Aachen University, Aachen, Germany; 3Department of Oral and Craniomaxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany

Dynamic contrast-enhanced (DCE) MRI enables non-invasive imaging characterisation of tissue vascularity. Therefore it is used for therapy monitoring in oncological studies especially for antiangiogenetic therapies. So it suggests itself to try this method also for in vivo assessment of onset and maintenance of angiogenesis in transplanted biomaterials. The aim of this case study was to evaluate the feasibility to monitor the transformation of the transplanted biomaterial especially with the focus on the formation of the vascular system using morphological and DCE MRI. The tested material was bovine bone matrix applied in a bilateral sinus lift procedure in combination with concentrated mononuclear cells including mesenchymal stem cells and autologous thrombin.

15:00         4365.     Quantitative Analysis of Pulmonary Perfusion Using First Pass Perfusion Magnetic Resonance Imaging

Jie J. Cao1, Yi Wang1,2, William Schapiro1, Jeannette McLaughlin1, Joshua Cheng1, Michael Passick1, Nathaniel Reichek1,2

1Research, St. Francis Hospital, Roslyn, NY, USA; 2Biomedical Engineering, SUNY, Stony Brook, NY, USA

Many pulmonary diseases affect pulmonary vasculature whether primarily or secondarily. In patients with advanced primary pulmonary hypertension pulmonary perfusion is marked reduced. Therefore quantitative pulmonary perfusion may be clinically useful in diagnosing pulmonary vascular abnormalities. In this study we investigated 2D dynamic contrast-enhanced magnetic resonance imaging (MRI) using a saturation recovery SSFP sequence to quantitatively analyze pulmonary perfusion in normal volunteers.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 80

13:30         4366.     Contrast Enhanced MRI Signal Dynamics of FUS-Induced BBB Opening in Mouse Brain

Axel Joachim Krafft1, Jürgen Walter Jenne2,3, Florian Maier1, Marie Nicole Krause4, Ana Martin-Villalba4, Peter E. Huber2, Wolfhard Semmler1, Michael Bock1

1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; 2Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; 3Mediri GmbH, Heidelberg, Germany; 4Molecular Neurobiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

The blood-brain barrier (BBB) is a cerebral cellular structure which is impenetrable for many therapeutic substances. Focused ultrasound has been demonstrated as a non-invasive tool for local and reversible BBB opening. MRI-guided BBB opening allows precise monitoring of signal changes after BBB disruption. The underlying dynamic processes of BBB opening are complex, and hence therapy control might be complicated. In this study, we compared short-term and long-term MRI signal dynamics of an interstitial and an intravascular MR contrast agent after BBB opening in mouse brain. Our results may help to define criterions for an optimized therapy control.

14:00         4367.     Dynamic Oxygen-Enhanced T1-Weighted MR in Tumour Xenografts

Inna Linnik1, Jose Ulloa2, Marietta Scott2, Carsten Liess2, Jane Halliday2, Josephine H. Naish1, John C. Waterton2,3, Geoffrey J.M. J.M. Parker1

1Imaging Science and Biomedical Engineering, Manchester University, Manchester, UK; 2Imaging, Translational Sciences, AstraZeneca, Alderley Park, Macclesfield, Cheshire, UK; 3Imaging Science and Biomedical Engineering, Manchester University, Manchester , UK

Oxygen-enhanced (OE) MRI has potential as a biomarker of oxygen tension, hypoxia, or radiation resistance in human tumours but the mechanisms of contrast have not yet been fully elucidated. T1-weighted MRI was performed in mouse xenografts (N=5) inhaling air, then oxygen, then air. All mice had large domains that exhibited immediate increase in signal following the switch to oxygen, consistent with the expected T1 decrease previously reported. However, there were also large domains where signal tended to decrease following the switch to oxygen.

14:30         4368.     A Population-Based AIF for Quantitative DCE-MRI of the Rat Abdomen Acquired Using Dynamic High Temporally and Spatially Resolved CT

Jonas Svensson1,2, Andreas Steingötter1, Markus Schwaiger1, Ernst Rummeny3, Rickmer Braren3

1Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; 2Medical Radiation Physics, Malmö University Hospital, Lund University, Malmö, Sweden; 3Department of Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany

DCE-MRI can be used for studies of tumor viability. The method requires an arterial input function (AIF) but with current MR techniques it is difficult to acquire an AIF that reliably describe the bolus dynamics in small animals. In this work a high temporal resolution, population-based AIF is acquired using a clinical CT scanner. The AIF is functionally modelled and successfully applied to quantitative DCE-MRI of 11 liver-tumor bearing rats resulting in stable Ktrans and ve values with low inter-animal variations. It is also shown that incorrect estimation of the peak contrast agent concentration could induce large errors in Ktrans.

15:00         4369.     Influence of Contrast-Dependent T2* Effects on DCE-MRI of the Prostate at 7T

Gregory J. Metzger1, Patrick J. Bolan1

1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA

The desire to perform DCE-MRI studies at ever increasing magnetic fields comes from the promise of increased spatial and temporal resolution. However, to effectively use DCE-MRI data at high fields, the increasing influence of T2* must be understood to avoid misinterpretation of results. Increased R2* (1/T2*) relaxivity and compartmentalization effects are shown to greatly change the shape of the contrast enhancement curves in both the vessel and tissue in prostate studies at 7T. Strategies to correct or mitigate these effects are necessary especially if pharmacokinetic modeling of ultra high field DCE-MRI studies is the goal.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 80

13:30         4370.     Functional Proton Electron Double Resonance Imaging: Concept and Experiment

Valery V. Khramtsov1, Keerthi Shet1, Eric Kesselring1, Sergey Petryakov1, Ziqi Sun1, Jay L. Zweier1, Alexandre Samouilov1

1Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, USA

A new concept of variable field proton electron double resonance imaging (VF PEDRI) is proposed. This allows for functional mapping using specifically designed paramagnetic probes (e.g. oxygen or pH mapping) within MRI high quality spatial resolution and short acquisition time. pH map of the phantom sample was extracted from only two PEDRI acquisitions performed at pre-selected EPR excitation fields. The data show at least 10 fold decrease in acquisition time for VF PEDRI compared with CW EPR imaging for the same phantom and similar functional resolutions. This is particularly important for in vivo applications where the experimental window and stability of the probes are limited.

14:00         4371.     Slice Selection Using Modulated Gradients for Fast 2D Single Point EPR Imaging

Nallathamby Devasahayam1, Sankaran Subramanian1, Shingo Matsumoto1, Murali Cherukuri Krishna1

1Radiation Biology, National Institutes of Health, Bethesda, MD, USA

We describe a novel slice selection strategy in 2D EPR imaging. Two and three dimensional in vivo EPR imaging and relaxation based oxymetry have been carried out routinely in our laboratory using the pure phase-encoding methodology of single point imaging, SPI. In this development we use the same imaging equipment operating at 300 MHz, with an additional provision of applying a low frequency (100 Hz) sinusoidal field along one of the gradient axes at nominal AC amplitude of about 1 mT/m. The modulation of the gradient along a particular axis introduces inhomogeneity along that axis everywhere except around the midpoint at which the amplitude is close to zero. A two dimensional phase encoding in a plane perpendicular to the axis of the modulated gradient retains coherent phase information only from the narrow slice at the center. Resolution of 5 mm and slice thickness of 5 mm is demonstrated.

14:30         4372.     Investigating DNP Markers for Stem Cell Tracking at Low Field

Li Sze Chow1, Behrouz Aflatoonian2, Harry D. Moore2, Martyn N.J. Paley1

1Academic Unit of Radiology, University of Sheffield, Sheffield, UK; 2Centre for Stem Cell Biology, Department of Biomedical Sciences, University of Sheffield, Sheffield, UK

This study investigated the use of a low field (8.2mT, 348kHz NMR frequency) dedicated MR system for Dynamic Nuclear Polarization (DNP) with 239MHz ESR frequency. The experiments have demonstrated the feasibility of imaging plant transpiration of 3-Carbomyl-PROXYL. We have also investigated stem cells tracking marked with a DNP tracer. Thus far no enhancement has been observed from the stem cell clusters but it could be due to the low number of stem cell clusters and thus large partial volume effect. There is also a possibility that the C-Proxyl may not have crossed the cell membranes or it had reacted with the culture medium.

15:00         4373.     The Resolution of Oxygen in EPR Images

Sankaran Subramanian1, Chandramouli Gadisetti1, Nallathamby Devasahayam1, Shingo Matsumoto1, Jeeva Munasinghe2, Murali C. Krishna1

1National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; 2NINDS, National Institutes of Health, Bethesda, MD, USA

Tissue oxygenation maps identifying normoxic and hypoxic areas are useful to understand tumor biology. Recent advances in EPR imaging have realized mapping of the tissue oxygenation in three dimensions. Co-registration of oxygen maps with images from other modalities facilitates examination of oxygen levels in sub-volumes or specific organs. However, understanding the contrasts of oxygen levels in different parts of the body requires knowledge of its resolution both in space and magnitude. The intrinsic resolution of pO2 is governed by the fundamentals of the imaging technique such as the gradient magnitude, relaxation times and oxygen sensitivity. Instrumental parameters including S/N ratio and field homogeneity and image reconstruction artifacts may also add to loss of resolution. Therefore it is necessary to define parameters to specify the resolution of oxygen levels, and present their estimates with digitally enhanced higher resolution images. The definition and determination of these resolution parameters of pO2 images are discussed

 


 
Hyperpolarized MR
Exhibit Hall 2-3                    Monday 14:00-16:00          Computer 81

14:00         4374.     Using Hyperpolarized [1-13C]Pyruvate as a Dynamic Marker for Intracellular PH

Marie Allen Schroeder1, Helen J. Atherton1, Lisa C. Heather1, Mark Aaron Cole1, Kieran Clarke1, George K. Radda1, Damian J. Tyler1

1Physiology, University of Oxford, Oxford, Oxfordshire, UK

As decreased pH is characteristic of myocardial ischaemia, the ability to dynamically monitor cardiac pH may be clinically important. This study assessed the validity of using hyperpolarized [1-13C]pyruvate, specifically the H13CO3-/13CO2 ratio, as a marker of intracellular pH in the isolated perfused heart. Intracellular 13C pH measurements made in healthy hearts, with 1 s temporal resolution, were validated using steady-state 31P MR spectroscopy (MRS). Additionally, pH equilibration showed distinct kinetic trends in healthy and post-ischaemic hearts. These results have indicated that H13CO3-/13CO2 could be a useful parameter to monitor alterations to cardiac metabolism that occur due to ischaemic heart disease.

14:30         4375.     Co-Polarization of (1-13C) Pyruvate and 13C Sodium Bicarbonate by Dynamic Nuclear Polarization Allows Simultaneous Assessment of in Vivo PH and Tumor Metabolism

David M. Wilson1, Kayvan Keshari1, Peder E. Larson1, Albert P. Chen2, Simon Hu1, Robert A. Bok1, Sarah J. Nelson1, Daniel B. Vigneron1, John Kurhanewicz1

1Department of Radiology, University of California, San Francisco, San Francisco, CA, USA; 2GE Healthcare

A new method for hyperpolarizing 13C- sodium bicarbonate was developed, and combined with a co-polarization approach that allowed dual polarization of both 13C sodium bicarbonate and [1-13C] pyruvate. Polarizations of 11% and 16% were achieved, respectively, with the corresponding T1’s 50 and 68s at 3T. Rapid equilibrium of injected 13C sodium bicarbonate with 13C CO2 allowed calculation of pH on a voxel by voxel basis, and tumor metabolism was observed by conversion of [1-13C] pyruvate to its metabolic products. These studies confirm the feasibilty of simultaneous measuring in-vivo pH and metabolism using nontoxic, endogenous species at clinically relevant field strengths.

15:00         4376.     Application of Slice-Localized 13C Dynamic MR Spectroscopy and 2D 13C Dynamic MR Spectroscopic Imaging with Hyperpolarized [1-13C]-Pyruvate in a Human Glioblastoma Xenograft

Ilwoo Park1,2, Peder E. Larson2, Janine M. Lupo2, Robert Bok2, Tomoko Ozawa3, John Kurhanewicz1,2, Daniel B. Vigneron1,2, C David James3, Sarah J. Nelson1,2

1Bioengineering, University of California, San Francisco/Berkeley, San Francisco, CA, USA; 2Surbeck Laboratory of Advanced Imaging, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA; 3Brain Tumor Research Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA

We have applied slice-localized 13C Dynamic MR Spectroscopy and 2D 13C multiband dynamic MR spectroscopic imaging following injection of hyperpolarized [1-13C]-pyruvate in order to monitor the real time metabolic dynamics of a human glioblastoma xenograft in rat model. The 2D dynamic CSI provided spatially resolved MRS that allowed for the differentiation of tumor from normal tissue based on the conversion of pyruvate to lactate. The results from this study showed potential for applying time-resolved MR spectroscopic imaging to characterize brain tumor models.

15:30         4377.     Alanine Signal and T2 Relaxation: A Potential Hyperpolarized 13C Metabolic Marker for Hepatocellular Carcinoma

Yi-Fen Yen1, dirk Mayer2,3, Patrick Le Roux4, Randy Lee King2, Dan Spielman2, Jim Tropp5, Adolf Pfefferbaum3,6, Ralph E. Hurd1, Shreyas Vasanawala2

1Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, USA; 2Department of Radiology, Stanford University, Stanford, CA, USA; 3Neuroscience Program, SRI International, Menlo Park, CA, USA; 4Global Applied Science Laboratory, GE Healthcare, Palaiseau, France; 5Global Applied Science Laboratory, GE Healthcare, Fremont, CA, USA; 6Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA

High alanine signal and long alanine T2 relaxation time were observed in rat liver tumors following hyperpolarized 13C-pyruvate injections. The measurements were performed on five tumor lesions in four rats. Reproducibility was assessed in normal livers in three control rats. The average T2 of normal livers and liver tumors is 0.6s and 1.2s, respectively. The 13C-alanine signal normalized to total 13C signal was found to be 2.1 times higher in liver tumors than in normal livers. 13C-alanine may be a new marker for liver tumors. Its diagnostic values in cancer detection and treatment monitoring are yet to be explored.

 
Exhibit Hall 2-3                    Tuesday 13:30-15:30          Computer 81

13:30         4378.     Selective Excitation of [13C]Bicarbonate Following Injection of Hyperpolarized [1-13C]Pyruvate Allows for Enhanced Signal

Crystal Harrison1,2, Matthew E. Merritt1, A Dean Sherry1,3, Craig Malloy1,4

1Advanced Imaging Research Center, UT Southwestern, Dallas, TX, USA; 2Physics Department, UT Dallas, Richardson, TX, USA; 3Department of Chemistry, UT Dallas, Richardson, TX, USA; 4Veterans Affairs, North Texas Health Care System, Dallas, TX, USA

Experiments using hyperpolarized substrates suffer from depolarization of the tracer by each detection pulse. The use of selective excitation Gaussian 90-degree pulses can increase the signal of [13C]bicarbonate derived from [1-13C]pyruvate in an isolated perfused mouse heart, allowing detection of metabolism through two enzyme catalyzed steps. Mouse hearts were perfused with 5 mM glucose and injected with a bolus of hyperpolarized [1-13C]pyruvate. 13C spectra were acquired every 5 seconds using either a hard 90-degree pulse or with a Gaussian 90-degree pulse. Enhanced [13C]bicarbonate signal is observed in the case of the Gaussian pulse.

14:00         4379.     Use of Hyperpolarized Carbon-13 Magnetic Resonance for Non-Invasive Observation of Metabolic Regulation

Marie Allen Schroeder1, Helen J. Atherton1, Lisa C. Heather1, Julian L. Griffin2, Kieran Clarke1, George K. Radda1, Damian J. Tyler1

1Physiology, University of Oxford, Oxford, Oxfordshire, UK; 2Biochemistry, University of Cambridge, Cambridge, Cambridgeshire, UK

Hyperpolarized 13C MR can effectively report on in vivo alterations to metabolism. However, the technique has yet to provide information regarding mechanisms of metabolic regulation. This study has demonstrated that by strategically manipulating systemic metabolism, via co-infusion of hyperpolarized [1-13C]pyruvate with other important metabolites, the nature of metabolic regulation can be determined non-invasively. We used hyperpolarized MR to distinguish two distinct mechanisms regulating in vivo flux through the enzyme pyruvate dehydrogenase via co-infusion of [1-13C]pyruvate with malate. Thus demonstrating that this non-invasive technique may be useful to indirectly follow complex mechanisms of metabolic regulation, in normal and diseased hearts.

14:30         4380.     Acute Liver Failure Studied by Hyperpolarized 1,4-13C2-Fumarate in CCl4 Injured Rat Liver

Rene in 't Zandt1, Magnus Karlsson1, Anna Gisselsson1, Pernille Rose Jensen1, Georg Hansson1, Mathilde Lerche1

1Imagnia AB, Malmö, Sweden

We have developed a diagnostic marker - hyperpolarized 1,4-13C2-fumarate, which takes advantage of the technique dynamic nuclear polarization for magnetic resonance imaging (DNP-MRI). This marker allows real-time metabolic studies of a TCA-cycle intermediate, 13C-malate. With this marker we have investigated the metabolism in the liver of CCl4 treated rats.

15:00         4381.     1,4-13C2 Malate Reports on Ischemia Related Reperfusion Injury, After Administration of Hyperpolarized 1,4-13C2 Fumarate in Mouse Skeletal Muscle in Vivo

Pernille Rose Jensen1, Rene in 't Zandt1, Magnus Karlsson1, Anna Gisselsson1, Georg Hansson1, Mathilde Hauge Lerche1

1Imagnia AB, Malmö, Sweden

Hyperpolarized 1-13C pyruvate has been used to visualize that the PDH flux is affected in the stunned myocardium in vivo and in vitro. Where metabolism of hyperpolarized pyruvate reports on ischemia related injury in the heart we have found that another metabolic marker, hyperpolarized 1,4-13C2 fumarate may be responsive on longer time scales and report on reperfusion injury. Hyperpolarized 1,4-13C2 fumarate was studied in an ischemic model in the resting mouse hind leg skeletal muscle and show the possible complementary value to pyruvate in reperfusion injury after an ischemic insult.

 
Exhibit Hall 2-3                    Wednesday 13:30-15:30          Computer 81

13:30         4382.     Rapid Hyperpolarized-Gas Lung Imaging Using a Parallel-Spiral Acquisition with BOSCO Reconstruction

Hao Tan1, Weitian Chen2,3, Peng Hu2,4, G. W. Miller5, T. A. Altes5, J. F. Mata5, E. E. de Lange5, G. D. Cates5,6, Ray F. Lee7, Craig H. Meyer2,5, John P. Mugler III2,5

1Electrical Engineering, University of Virginia, Charlottesville, VA, USA; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, USA; 3now with GE Healthcare; 4now with Beth Israel Deaconess Medical Center; 5Department of Radiology, University of Virginia, Charlottesville, VA, USA; 6Physics, University of Virginia, Charlottesville, VA, USA; 7Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA

We developed two variable-density parallel-spiral sequences with parallel image reconstruction based on successive convolution operations (BOSCO) reconstruction for rapid lung imaging using hyperpolarized 3He. These sequences yielded images with spatial resolution and image quality comparable to standard GRE images. We also developed the first BOSCO image reconstruction technique for single-shot spiral, using inverse gridding for BOSCO training. Future work will concentrate on optimizing the flip angles to maximize SNR, and on developing a 3D parallel-spiral acquisition.

14:00         4383.     Ultrahigh Temporal Resolution Dynamic Imaging of He-3 MRI Using Bolus Delivery

Rafael Luis O'Halloran1, James H. Holmes1,2, Eric T. Peterson3, Ronald L. Sorkness4, Mark L. Schiebler5, Sean B. Fain1,5

1Medical Physics, University of Wisconsin, Madison, WI, USA; 2Applied Science Laboratory, GE Healthcare, Waukesha, WI, USA; 3Biomedical Engineering, University of Wisconsin, Madison, WI, USA; 4School of Pharmacy, University of Wisconsin, Madison, WI, USA; 5Radiology, University of Wisconsin, Madison, WI, USA

Dynamic hyperpolarized He-3 imaging of the lung using 2D radial acquisition and Iterative HYPR reconstruction is performed in healthy volunteers. The combination of highly undersampled radial acquisition and iterative reconstruction provides a temporal resolution of 20 ms or 50 frames per second, allowing subtle patterns of differential lung filling to be visualized. Parametric maps are calculated from the time resolved image data.

14:30         4384.     Selective Saturation of Xe Dissolved Into Tissue and Xe Bound with Hemoglobin in Human Lungs in Hyperpolarized 129Xe MR

Yulin Chang1, Talissa A. Altes1, Isabel M. Dregely2, Stephen Ketel3, Iulian C. Ruset2,3, Jaime F. Mata1, F. William Hersman2,3, John P. Mugler III1, Kai Ruppert1

1Radiology, University of Virginia, Charlottesville, VA, USA; 2Physics, University of New Hampshire, Durham, NH, USA; 3Xemed LLC, Durham, NH, USA

In humans Xe dissolved into lung tissue and Xe bound with hemoglobin have distinct resonance frequencies at 197 ppm and 217 ppm, respectively. In studies of the gas exchange processes in the lung it is often desirable to selectively saturate either individual dissolved-phase peak. RF pulses centering at various frequencies and with different pulse durations were tested at both 1.5 T and 2.9 T fields for this purpose.

15:00         4385.     Hyperpolarized 129Xe MR of the Sickle Cell Disease: Preliminary Findings

Yulin Chang1, Talissa Altes1, Isabel M. Dregely2, Stephen Ketel3, Iulian C. Ruset2,3, Jaime F. Mata1, F. William Hersman2,3, John P. Mugler III1, Kai Ruppert1

1Radiology, University of Virginia, Charlottesville, VA, USA; 2Physics, University of New Hampshire, Durham, NH, USA; 3Xemed LLC, Durham, NH, USA

Sickle cell disease (SCD) is characterized by the sickle-shaped red blood cells that obstruct capillaries. MR of hyperpolarized 129Xe can distinguish Xe bound with hemoglobin from the gas-phase Xe and Xe dissolved into lung tissue. The spectrum of dissolved-phase Xe in SCD patients are compared with that of a normal subject. Xe exchange spectroscopy and Xe transfer contrast (XTC) imaging methods were also applied and compared with normal subjects.

 
Exhibit Hall 2-3                    Thursday 13:30-15:30          Computer 81

13:30         4386.     More Than 50 % 13C Polarization in Solution by the DNP-NMR Method: 200,000-Fold Enhancement Compared to 3 T and Room Temperature

Jan Henrik Ardenkjaer-Larsen1, Sven Macholl1, Haukur Johannesson1

1GE Healthcare, Amersham, UK

The DNP method for hyperpolarizing nuclear spins in molecules in solution can still be significantly improved in terms of achieved polarization. So far, a polarization of 10-30 % has typically been obtained in the liquid state with the current instrumentation. In this work we demonstrate two different means of further enhancing the polarization in the solid state. One method is by changing the magnetic properties of the sample, the other is by changing the field and temperature of the polariser. The methods are exemplified by several molecules of particular biological interest and liquid state polarization of more than 50 % is demonstrated.

14:00         4387.     DNP and EPR Properties of a Biocompatible Macromolecule for EPRI and in Vivo MRI

Björn Dollmann1, Andrei Kleschyov2, Kerstin Münnemann1,3, Dariush Hinderberger1

1Max Planck Institute for Polymer Research, Mainz, Germany; 2Institute of Pharmacology, Johannes Gutenberg University, Mainz, Germany; 3Section of Medical Physics, Johannes Gutenberg University, Mainz, Germany

A versatile and biocompatible class of macromolecules with four different labeling degrees and positions is presented and investigated by DNP and three complementary EPR methods. DNP enhancement factors for these spin-labeled heparin molecules are measured as a function of microwave power and the projected maximum enhancement factors are compared. The macromolecule with an intermediate labeling degree shows the best DNP efficiency and 1H DNP enhancement factors up to -91 were observed. The EPR spectra let us conjecture that the spin-labeled heparin can be seen as a “broad-band” polarizing agent that might also be suitable for an efficient hyperpolarization of 13C.

14:30         4388.     PASADENA Hyperpolarization: Instrumentation and Preparation of Tracers for in Vivo Application

Jan-Bernd Hövener1,2, Eduard Chekmenev1,3, Larry Robertson1, Kent Harris1, Thao Tran1, William Perman4, Brian Ross1, Pratip Bhattacharya1

1Enhanced Magnetic Resonance Laboratories, Pasadena, CA, USA; 2Medical Physics in Radiology, DKFZ, Heidelberg, Germany; 3California Institute of Technology, Pasadena, CA, USA; 4St. Louis University, School of Medicine, St. Louis, USA

In the dawn of hyperpolarization for biomedical application, the question of suitable instrumentation arises. PASADENA is presently installed only in few places, possibly because only few molecules and no instrumentation is available. We present a polarizer for the reliable hyperpolarization various molecules, including novel molecules 1-13C, 2,3-D2 Succinate (Suc) and TFPP, a target specific agent. Reproducibility and yield of hyperpolarized Suc using the new apparatus was determined to = (0.064 ± 0.02), t = (33 ± 0.5) s after sample production. By measurement of T1(4.7 T) = (39.6 ± 0.6) s, the nascent level was estimated to &#61627; 15 %.

15:00         4389.     Optimization of 89Y DNP

Zoltan Kovacs1, Steven Reynolds2, Matthew E. Merritt3,4

1AIRC, University of Texas Southwestern Medical Center, Dallas, TX, USA; 2Oxford Instruments Molecular Biotools, Oxford, UK; 3Advance Imaging Research Center, UT Southwestern Med. Center, Dallas, TX, USA; 4Radiology, UTSW Medical Center, Dallas, TX, USA

Metabolically sensitive imaging agents promise to transform the diagnostic capabilities of MRI. Yttrium-89 is an attractive nucleus for DNP studies due to its extremely long T1. Yttrium is isostructural to gadolinium, and so could serve as the basis for a variety of contrast agents using previously developed ligands but with the added capability of direct detection. Yttrium DNP is optimized in this study and a new method of polarization is suggested.