Traditional Posters : Body (Non-Cancer) Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Liver - Pancreas

Monday May 9th
Exhibition Hall  14:00 - 16:00

794.   Quantifying Blood Flow and Perfusion in Liver Tissue using Phase Contrast Angiography and Arterial Spin Labelling. 
Caroline Hoad1, Carolyn Costigan1, Luca Marciani2, Philip Kaye3, Robin Spiller2, Penny Gowland1, Guru Aithal2, and Susan Francis1
1School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom, 3Department of Cellular Pathology, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom

Phase contrast angiography of the portal vein and multi-slice True-FISP FAIR arterial spin labelling were used to measure hemodynamic parameters in 36 chronic liver disease patients. Reproducibility of these parameters was assessed in 5 healthy volunteers. Perfusion values were determined on a voxel-by-voxel basis. Portal vein mean flux and velocity across the cardiac cycle were also determined. A large inter-subject variability of these hemodynamic parameters was found across the liver patients, whereas the intra-subject variability was found to be much smaller. These techniques have the potential to monitor non-invasively the hemodynamic changes in the liver associated with liver fibrosis and cirrhosis.

795.   Toward non-invasive estimation of portal pressure via MR Elastography 
Sara Aristizabal1, Meng Yin1, Kevin J. Glaser1, Arunark Kolipaka1, Armando Manduca1, and Richard L Ehman1
1Mayo Clinic, Rochester, Minnesota, United States

Portal hypertension is an important complication of chronic liver disease, and estimates of status of portal blood pressure elevation are regarded as important for management. This study evaluated the hypothesis that splenic stiffness assessed with MR Elastography is systematically related to splenic pulp pressure. The mechanical properties of seven resected ex-vivo pig spleens under varying splenic vein pressures were evaluated using MRE. A systematic increase in splenic stiffness with increase in pulp pressure was observed, providing preliminary evidence that MRE may provide a unique non-invasive method for estimating portal venous pressure.

796.   Multiexponential T2 Analyses in a Murine Model of Hepatic Fibrosis at 11.7T MRI 
Jonathan Scalera1, Hernan Jara1, Jorge A Soto1, James A Hamilton2, Michael O'Brien3, and Stephan William Anderson1
1Radiology, Boston University Medical Center, Boston, MA, United States, 2Physiology and Biophysics, Boston University Medical Center, 3Pathology and Laboratory Medicine, Boston University Medical Center

Purpose: To characterize the multiexponential T2 (MET2) relaxation of liver using a murine model of hepatic fibrosis. Methods: 3,5-dicarbethoxy-1,4-dihydrocollidine(DDC) was utilized to induce hepatic fibrosis. Ex vivo liver specimens were imaged using 11.7T MRI and MET2 analyses were carried out using two algorithms. Findings were compared to degrees of liver fibrosis. Results: Two distinct peaks were seen, a dominant, short T2 and a minor, long T2 component. Moderate correlation was seen between the long T2 peak and degrees of fibrosis. Conclusion: MET2 relaxation offers potential for evaluating the microenvironment in liver fibrosis with implications for noninvasive characterization of liver disease.

797.   Assessment of liver fibrosis in rats with MR imaging and elastography 
Heiko G. Niessen1, Michael Neumaier1, Thomas Kaulisch1, Ingolf Sack2, Dieter Klatt3, Thomas Klein4, Juergen Braun3, and Detlef Stiller1
1In-Vivo Imaging, Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany, 2Dept. of Radiology, Charite-University Medicine Berlin, 3Dept. of Medical Informatics, Charite-University Medicine Berlin, 4CardioMetabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany

Magnetic Resonance Elastography (MRE) is a promising tool to distinguish steatohepatosis from fibrosis and to differentiate various stages of fibrosis. Here, rats were fed with a combined methionine-choline-deficient (MCD) and high-fat diet (HFD) to induce liver fibrosis. Age-dependent alterations were investigated with MRE, imaging (T2, ADC), and spectroscopy. For MRE a newly developed hydraulic-based actuator was used. MRE yields a significantly different storage and loss modulus in the rat liver after MCD/HF-diet. In addition, T2 is significantly increased, the ADC reduced compared to control animals. However, the magnitude of the latter effects is smaller than those obtained with MRE.

798.   Time-resolved Qualitative and Quantitative Analysis of Normal and Altered 3D Portal Venous Hemodynamics in Liver Cirrhosis Patients 
Zoran Stankovic1, Zoltan Csatari1, Peter Deibert2, Wulf Euringer1, Susanne Eggerking2, Philipp Blanke1, Zahra Abdullah Zadeh1, Mathias Langer1, and Michael Markl1
1Radiology, University Hospital Freiburg, Freiburg, Ba.-Wü., Germany, 2Gastroenterology, University Hospital Freiburg, Freiburg, Ba.-Wü., Germany

Flow-sensitive 4D MRI was applied for the qualitative and quantitative analysis of portal venous hemodynamics of liver cirrhosis patients (n=20) and volunteers (n=41). Our results revealed a significant correlation of 4D MRI with the reference standard Doppler Ultrasound for maximum and mean velocities and flow for the intrahepatic vessels. Quantitative flow analysis could be performed retrospectively at any location of interest and revealed significant alterations in velocities and flow in patients compare to age matched and younger control groups.

799.   Evaluation of of Normal and Altered Hepatic Arterial und Portal Venous 4D Hemodynamics in Patients with Liver Cirrhosis before and after Treatment with TIPS 
Zoltan Csatari1, Zoran Stankovic2, Peter Deibert2, Wulf Euringer2, Julia Geiger2, Wolfgang Kreisel2, Mathias Langer2, and Michael Markl2
1University Hospital Freiburg, Freiburg, Baden Württemberg, Germany, 2University Hospital Freiburg

Flow-sensitive 3-dimensional magnetic resonance imaging was successfully used for simultaneous visualization and quantification of flow characteristics in the complete hepatic arterial und portal venous system in healthy volunteers and in patients with liver cirrhosis before and after treatment with transjugular intrahepatic portosystemic shunt (TIPS). As expected, considerable changes in blood flow characteristics after treatment with TIPS were evident. Although agreement to the reference standard Doppler ultrasound was limited, our results demonstrate the feasibility of time-resolved 3D phase contrast MRI for evaluation of normal and pathological vascular hemodynamics of the great hepatic vessels.

800.   Performance and limitations of R2* relaxometry liver iron measurements 
Greg Colin Brown1, David James Taylor1, and Donald McRobbie2
1Radiology, Royal Adelaide Hospital, Adelaide, South Australia, Australia, 2Radiological Sciences Unit, Imperial College Healthcare NHS Trust, London, United Kingdom

Accurate measurement of liver iron concentration (LIC) is critical in the management of iron overload states, drug development, and understanding iron loading physiology. R2 and R2* relaxometry are the predominant non invasive methods. We investigate the performance of R2* relaxometry using FerriScan R2 relaxometry as the reference standard. Results indicate that R2* relaxometry, in its current form, has a problematic “saturation threshold” that has not been described previously in liver R2* relaxometry. When used with published calibration equations the R2* method substantially underestimates LIC above moderate levels, thus restricting its clinical utility.

801.   Influence of a connected and inactive coil on a MR exam: liver iron load measurement 
Anou Sewonu1,2, Marine Beaumont3,4, Fanny Carbillet1, Maélène Lohezic2, René Anxionnat4, Jacques Felblinger2,4, and Gabriel Hossu3,4
1Alara-Solutions, Strasbourg, France, 2IADI Lab., Nancy-Université, Nancy, France, 3CIT801, INSERM, Nancy, France, 4IADI Lab., CHU Nancy, Nancy, France

Quality assurance of liver iron assessment requires knowledge of a connected but inactive coil effects on the exam. Four volunteers were investigated on a 1.5T MR unit in body coil with an inactive torso coil plugged and then in body coil only. A signal-based method and a R2* method for liver iron measurement were used. Image quality was also assessed. Liver to muscle signal ratio and contrast were significantly decreased for body coil only measurement. R2* did not show any significant difference. Further investigation involving more subjects is required for confirming these promising outcomes.

802.   Blood-Suppressed T2* Mapping in Liver with Motion Sensitized Driven Equilibrium (MSDE) 
Rexford D Newbould1, and Giulio Gambarota1
1GSK Clinical Imaging Centre, Hammersmith Hospital, London, United Kingdom

T2* mapping of the liver can be used to assess iron loading, which is relevant in a number of diseases including thalassemia, hereditary hemochromatosis, and sickle cell disease. However, with no innate flow suppression, multi-echo spoiled gradient echo (SPGR) sequences suffer from artifacts originating from flowing blood spins. This work combines a motion-sensitized driven equilibrium (MSDE) preparation with multi-echo SPGR to suppress the blood signal intensity in breath-hold T2* mapping of the liver. Flow suppression is tested in a healthy volunteer, and T2* maps are acquired in five volunteers.

803.   Evaluation of individual versus average T2* decay correction and single slice versus multislice sampling in the two-point Dixon method for liver fat quantification 
Cemil Kirbas1, Eric Zalusky1, Stefan Czerwinski2, Miryoung Lee2, Ke Cheng Liu3, and Jason G Parker1
1Innovation Center, Kettering Health Network, Kettering, OH, United States, 2Department of Community Health, Wright State University, Kettering, OH, United States, 3Siemens Medical Solutions, United States

Assessment of fat content in the liver is of interest in the evaluation of a spectrum of diseases. Quantification of liver fat fraction using magnetic resonance imaging (MRI) has become popular recently. One of the popular MRI methods to quantify liver fat fraction is the two-point Dixon method using in-phase (IP) and out-phase (OP) images. In this study we used a Dixon-based method and evaluated the difference between using individual correction factor calculated for each subject and an average correction factor. We also evaluated the accuracy of fat fraction calculation using a ROI’s from a single slice versus multiple slices.

804.   Quantification of Hepatic Steatosis with MRI: Histological Validation 
Thomas David Reed1, Rashmi Agni2, Catherine Hines1, Richard Bruce1, Mona Ranade1, Benjamin Soriano2, Kiyarash Mohajer1, and Scott B Reeder1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Pathology, University of Wisconsin, Madison, WI, United States

Over the last several years, quantitative MR methods for accurate measurement of hepatic steatosis have been developed. The majority of studies validated quantitative MR methods using single voxel MRS as the reference standard. These methods have demonstrated excellent correlation and agreement between proton density fat-fraction and MRS so long as all confounding factors (eg. T1, T2*, spectral complexity of fat, noise bias and eddy current correction) are addressed. However, there is a paucity of tissue validation in these studies. In this retrospective study involving 26 patients, we demonstrate good correlation (r2=0.77) between MRI fat-fraction and histological grading of steatosis.

805.   Relationship between Proton-Density Fat-Fraction and True Fat Concentration for In Vivo Fat Quantification with Magnetic Resonance Imaging 
Scott Brian Reeder1, Catherine D Hines1, Huanzhou Yu2, Charles A McKenzie3, and Jean H Brittain4
1Radiology, University of Wisconsin, Madison, WI, United States, 2Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada, 4Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States

Proton density fat-fraction (PDFF) is a useful metric for fat quantification, providing a platform- and protocol-independent metric of tissue fat concentration. PDFF is the ratio of unconfounded signal from mobile fat protons, normalized by the total unconfounded signal from mobile fat protons and mobile water protons. Unfortunately, reference assays that measure concentrations of triglycerides do not account for NMR invisible species, and therefore will correlate, but may not agree directly with, PDFF measured with MRI. In this work, the relationship between true tissue fat concentration and PDFF is described and validated using a fat-water-deuterium oxide phantom.

806.   In Vivo Application of Breath-hold Single-Voxel 1H Spectroscopy for T2-Corrected Hepatic Lipid Measurement: Evaluation of Accuracy and Reproducibility 
Puneet Sharma1, Hiroumi D Kitajima1, Xiaodong Zhong2, Bobby Kalb3, Alton B Farris4, Miriam B Vos5, and Diego R Martin3
1Radiology, Emory Healthcare, Atlanta, GA, United States, 2MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 3Radiology, Emory University, Atlanta, GA, United States,4Pathology, Emory University, Atlanta, GA, United States, 5Hepatology, Children's Hospital of Atlanta, Atlanta, GA, United States

Therapy development for early disease has required accurate and reproducible measurement for the longitudinal monitoring of hepatic lipid. Recently, a multi-echo breath hold T2-corrected MR spectroscopy technique (HISTO-MRS) has demonstrated clinical feasibility, while proving robust in phantom validation of lipid content. This investigation extends these initial observations for a more broad evaluation of accuracy and reproducibility in a clinical setting. The results showed that the HISTO technique was highly reproducible, while significantly correlating with biopsy measures, allowing effective longitudinal assessment of hepatic lipid. Combined with efficient and automated post-processing steps, HISTO-MRS demonstrates clinical applicability as a biopsy surrogate.

807.   Respiratory Gated Contrast Enhanced Imaging of the Liver 
Pascal Spincemaille1, Doug Brylka1, Martin R Prince1, and Yi Wang1,2
1Radiology, Weill Cornell Medical College, New York, NY, United States, 2Biomedical Engineering, Cornell University, Ithaca, NY, United States

Dynamic contrast enhanced liver imaging is used for the detection and characterization of liver lesions. Current clinical protocols rely on a multiple phase approach acquired over multiple breath-hold, limiting spatial and temporal resolution. In a considerable subset of patients, decreased breath-holding ability leads to a dramatic decrease in image quality. In this work, a 3D hybrid Cartesian-radial acquisition is combined with respiratory gating to suppressed motion related artifacts

808.   Development of MRI-Guided Intrabiliary Local Agent Delivery Technique 
Feng Zhang1, Jiakai Li1, Yanfeng Meng1, Jihong Sun1, Stephanie San Juan Soriano1, Huidong Gu1, Patrick Willis1, and Xiaoming Yang1
1Image-Guided Bio-Molecular Intervention Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA, United States

This study was to develop a new technique of intrabiliary MRI-guided local agent delivery. We first confirmed the capability of motexafin gadolinium(MGd) entering cholangiocarcinoma cells. Then, we established surgical protocol for intrabiliary balloon-mediated MGd delivery into pig common bile duct (CBD) walls ex vivo. We finally validated the feasibility of using MR to monitor, in vivo, intrabiliary delivery of MGd into the pig CBD wall of a pig, which was confirmed by subsequent MRI-histology correlation. This new technique may open new revenues for MR-guided intrabiliary local delivery of therapeutics, such as genes and drugs, to treat malignant pancreatobiliary diseases.

809.   Evaluating the effects of various food ingredients on gallbladder contraction 
Eleanor F Cox1, Caroline L Hoad1, John J Totman1, Carolyn Costigan1, Luca Marciani2, Robin C Spiller2, and Penny A Gowland1
1SPMMRC, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2NDDC NIHR BRU, Nottingham University Hospitals, Nottingham, United Kingdom

Different food ingredients can trigger gallbladder contraction but which food ingredients are most effective in contracting the gallbladder and at which dose level is not well understood. Here we used serial MRI to test the ability of several food ingredients to stimulate gallbladder contraction. High fat emulsion and semi-skimmed milk stimulated the highest gallbladder contraction (42% and 41% contraction respectively) of 10 test drinks, which also had the highest fat content. A fat-dose response of the gallbladder was subsequently shown using a milk-based drink, varying only the fat content, and correlated with changes in plasma cholecystokinin.

810.   Investigating the Pancreatic Function: Robust 3D MR imaging of Mouse Abdomen 
Ekkehard Küstermann1, Anke Meyer2, Amod Godbole2, Wolfgang Dreher3, and Kathrin Maedler2
1ZKW, University of Bremen, Bremen, Germany, 2CBIB, University of Bremen, 3FB2, University of Bremen

Diabetes research strongly benefits from non-invasive methods of analysing pancreatic beta-cell mass. A promising strategy is to measure Manganese uptake in pancreatic tissue by T1-weighted in-vivo MR imaging. Here, a “3D ir-Snapshot-FLASH” protocol for robust, least-invasive T1-weighted MR imaging of mouse abdomen in spontaneously braething mice is presented.

811.   MRI of Paraduodenal Pancreatitis: Clinical Performance in Distinction From Carcinoma 
Bobby Kalb1, Juan M Sarmiento2, N Volkan Adsay3, James Costello1, Hiroumi Kitajima1, Puneet Sharma1, Christina Lurie1, and Diego R Martin1
1Radiology, Emory University School of Medicine, Atlanta, GA, United States, 2Surgery, Emory University School of Medicine, Atlanta, GA, United States, 3Pathology, Emory University School of Medicine, Atlanta, GA, United States

Paraduodenal pancreatitis (PDP) is a clinicopathologically distinct form of focal chronic pancreatitis (CP) thought to be related to obstruction of the pancreatic accessory duct. Differentiation between PDP and pancreatic duct adenocarcinoma (CA) is challenging and represents an important unmet clinical need. Our results demonstrate PDP may be distinguished from CA with contrast-enhanced MRI even with non-experienced readers, with a sensitivity of 88.2% and specificity of 86.7%, when strict diagnostic criteria are followed. Our study contributes to optimized therapeutic management of patients with a pancreatic head mass, supporting a primary diagnostic role for MRI.

812.   Assessment of Chronic Pancreatitis with MR Elastography 
Yogesh kannan Mariappan1, Kevin Glaser1, Naoki Takahashi1, Phillip Young1, and Richard L Ehman1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States

Magnetic Resonance Elastography (MRE) is a phase-contrast MR elasticity imaging technique that can noninvasively measure the shear stiffness of soft tissues. The hypothesis of this work was that the stiffness of the pancreas in patients with pancreatitis is significantly different from the stiffness of healthy pancreas and that MRE can used to detect this difference. To test this hypothesis, an MRE acquisition was implemented to acquire multislice vector shear wave displacement data to measure the shear stiffness of the pancreas. This approach was applied to healthy subjects and to patients suspected of having pancreatic disease. Preliminary data obtained from this study indicates that the stiffness of the pancreas in patients with chronic pancreatitis is higher than in healthy volunteers.

813.   Ethnic implications of pancreatic steatosis 
Lidia S Szczepaniak1, Edward W Szczepaniak1, Qi Peng2, and Ildiko Lingvay3
1The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States, 2Radiology, University of Texas, Health Science Center, San Antonio, Texas, United States,3Endocrinology, University of Texas, Southwestern Medical Center, Dallas, Texas, United States

Ethnic minorities – African American and Latinos – are disproportionally affected by obesity and type 2 diabetes for reasons not completely understood. We present here results of our study designed to provide new insights into understanding the mechanism of beta cell dysfunction. We focused on the role of fat deposition in the pancreas (pancreatic steatosis). We used localized proton MRS to measure pancreatic steatosis in vivo and frequently sampled IV glucose tolerance test to measure insulin secretion. We detected diverse patterns of pancreatic fat storage that may contribute to ethnic variations in pathogenesis of insulin secretion.

Traditional Posters : Body (Non-Cancer) Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.

Tuesday May 10th
Exhibition Hall  13:30 - 15:30

814.   Variation in GFR estimates derived from DCE-MRI renography studies in the presence of reduced Signal to Noise Ratio 
Saeed Kiani1, Isky Gordon2, Iosif Mendichovszky3, Marica Cutajar2, and Kevin Wells1
1CVSSP, Faculty of Engineering & Physical Sciences, University of Surrey, Guildford, Surrey, United Kingdom, 2UCL Institute of Child Health, London, United Kingdom, 3Wolfson Molecular Imaging Centre, University of Manchester, Manchester, United Kingdom

Robustness of DCE-MRI renography in the presence of diminished renal function needs to be addressed. Renal impairment may result in uptake reduction of the contrast agent (Gd-DTPA) and subsequently signal-to-noise ratio (SNR) reduction in the DCE-MR image data. This work aims to evaluate the robustness of DCE-MRI renography in the presence of synthetic SNR variation on the renal data. The synthetic SNR variation is achieved by degrading the data in both spatial and temporal domains. The results demonstrated substantial variations (i.e. >10%) in estimated kidney filtration rates (GFR) for a slight variation of SNR, about 0.05-0.1, from the original data.

815.   A variational approach to image registration in DCE-MRI of human kidney 
Andreas D Merrem1, Frank G Zoellner1, and Lothar R Schad1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany

DCE-MRI is an emerging technique for a more accurate assessment of local renal function. Measured time-intensity-curves used for quantification of kidney function are hampered by respiratory motion. We analysed the feasibility of a variational approach to image registration in DCE-MRI. Evaluation was performed by checkerboards, measuring the vertical displacement of an anatomical reference point, and fitting a 2-compartment model to a ROI in the renal cortex. Registration was successful for 4 out of the 5 data sets. The motion could be reduced to below the in-plane resolution of 1.5mm. The Akaike error of fitting the 2-compartment model is reduced up to 24%.

816.   A Robust Method for Reducing Inflow Artifacts in the Arterial Input Function of Dynamic Contrast Enhanced Data Sets 
Yutong Duan1,2, Ralf Berthold Loeffler1, Ruitian Song1, Aaryani Tipirneni1, Sheri Spunt3, Niels Oesingmann4, Anne Viano2, and Claudia Maria Hillenbrand1
1Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, United States, 2Physics, Rhodes College, Memphis, TN, United States, 3Oncology, St. Jude Children's Research Hospital, Memphis, TN, United States, 4Siemens Medical Solutions USA, Inc., New York, NY, United States

This study includes techniques that smooth the curve by removing the spikes from the curve, and a simulation test that validates this optimization with multiple sets of noise reproducing the inflow effect.Four sets of artificial noise were extracted from real patient data and used to simulate the abrupt spikes due to the inflow effect. After noise was applied the GFR values were calculated and compared with the reference GFR. The correlation between the original AIF and the two gamma variate function varied from 0.95 to 0.99. The smoothing method was able to reduce the inflow artifact on the AIF signal.

817.   Quantification of renal DCE-MRI with BLADE: Initial experience 
Florian Lietzmann1, Frank G. Zoellner1, Ulrike Attenberger2, Henrik J. Michaely2, Stefan Haneder2, Stefan O. Schoenberg2, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Institute of Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Mannheim, Germany

Dynamic contrast enhanced MRI (DCE-MRI) provides an alternative technique to evaluate kidney function such as perfusion or glomerular filtration parameters. The self-navigating BLADE-sequence offers an alternative approach for a motion corrected DCE-examination without the need of respiratory triggering. The aim of this study was to evaluate whether kidney functional parameters can be reliably derived from a pharmacokinetic model while providing improved motion correction based on the BLADE algorithm.

818.   Comparison of ASL and DCE-MRI for renal perfusion measurements 
Jeff D Winter1,2, Keith S St. Lawrence3,4, and Hai-Ling Margaret Margaret Cheng1,5
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada, 2Research and Development, IMRIS, Winnipeg, Manitoba, Canada, 3Imaging Division, Lawson Research Institute, London, Ontario, Canada, 4Medical Biophysics, University of Western Ontario, London, Ontario, Canada, 5Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

The injury or loss of renal microvessels is a determinant of renovascular disease severity. Assessment of renal microvasculature may be achieved using MR perfusion techniques including quantitative DCE and ASL. This study compared renal perfusion estimates for ASL and DCE MRI. DCE MRI was performed with a dual-bolus contrast injection for improved arterial input sampling. We found DCE estimates of renal cortex perfusion (3.57 ± 0.96 ml/g/min) were in agreement with ASL (3.28 ± 0.59 ml/g/min). Moreover, this study showed feasibility of the dual bolus approach for quantitative DCE for the first time outside of cardiac imaging.

819.   A Comparative Study of Arterial Spin Labeling and Dynamic Contrast Enhanced Perfusion Magnetic Resonance Imaging in the Kidneys 
Mao-Yuan Su1, Chin-Chen Chang1, Kao-Lang Liu1, Ting-Fang Tiffany Shih1, and Wen-Chau Wu1,2
1Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 2Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan

To the best of our knowledge, cross-validation between ASL and DCE remains absent for the kidneys. In the present study, we examined the compatibility of ASL and DCE at the field strength of 3T by measuring renal blood flow with both techniques on a sample of healthy volunteers and one patient with renal artery stenosis. Correlation was found between ASL and DCE measurements (r = 0.9, p < 0.005). Both ASL and DCE were able to distinguish the reduced RBF in the patient with renal artery stenosis. We conclude that ASL and DCE provide compatible measurement of renal perfusion at 3T.

820.   High Resolution Respiratory Triggered Multiphase TrueFISP ASL 
Eleanor F Cox1, Caroline L Hoad1, and Susan T Francis1
1SPMMRC, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

A respiratory triggered variant of multiphase TrueFISP arterial spin labelling (ASL) is introduced to measure renal perfusion and transit time across the kidney at high spatial resolution. The increase in spatial resolution reduces partial volume effects allowing the visualisation of progressive inflow of labelled blood to the kidney and assessment of heterogeneity across the kidney, important in the study of renal physiology and disease. From the high resolution data the mean perfusion across the cortex was 329 ± 85 ml/100g/min and the mean transit time was 472 ± 178 ms.

821.   Model-Based Registration for Motion Correction of Inversion Recovery and Multiple-Time Point Renal ASL 
Mark Stephen Dobbs1,2, Neil Woodhouse3, Geoff J.M Parker1,2, and Josephine H Naish1,2
1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom, 2The Biomedical Imaging Institute, The University of Manchester, Manchester, Greater Manchester, United Kingdom, 3AstraZeneca, Macclesfield, Cheshire, United Kingdom

There has been increasing interest in applying perfusion measurement techniques, such as Arterial Spin Labelling (ASL), to the kidneys in light of concerns over the link between gadolinium-bearing contrast agents and nephrogenic systemic fibrosis (NSF). Correction or avoidance of breathing-induced motion artefacts in the kidneys is beneficial. Recent work has shown that multiple-time point and multiple phase approaches for ASL can aid renal perfusion quantification by extracting the bolus arrival time (the time for labelled blood to reach the renal tissue), which itself may have clinical relevance. When combining a multiple-time point approach with presaturation, there are large contrast differences in the raw ASL images at different inversion times (TIs), relative to the ASL signal, which makes registration problematic. This is also a problem for inversion recovery (IR) sequences applied to the kidneys. In this abstract we demonstrate the feasibility of a model-based registration approach, based on the T1-recovery of signal intensities, for registration of multiple-time point ASL and IR sequences applied to the kidneys.

822.   k-means Segmentation of Kidney Cortex and Medulla for BOLD Images 
Yin Huang1, Nathan Hanson1, Elizabeth Sadowski2, David Niles1, Nathan Artz1, Arjang Djamali3, Thomas Grist1,2, and Sean Fain1,2
1Medical Physics, University of Wisconsin Madison, Madison, WI, United States, 2Radiology, University of Wisconsin Madison, Madison, WI, United States, 3Nephrology, University of Wisconsin Madison, Madison, WI, United States

The k-means segmentation method was implemented to semi-automatically segment kidney cortex and medulla for MR BOLD images of 6 subjects. By acquiring an extra T1 weighted image, k-means segmentation was performed based on two kidney feature values -- T1 and T2* weighted signal intensities. Manual segmentation results on the same subjects were used as reference and sensitivity and specificity measures were calculated to evaluate the quality of the k-means segmentation.

823.   Longitudinal Evaluation of Renal Oxygenation in Kidney Donors and Recipients Using BOLD MRI 
David Joseph Niles1, Sean B Fain1,2, Nathan S Artz1, Yin Huang1, Karl K Vigen2, Arjang Djamali3, Thomas M Grist1,2, and Elizabeth A Sadowski2
1Medical Physics, University of Wisconsin, Madison, WI, United States, 2Radiology, University of Wisconsin, Madison, WI, United States, 3Nephrology, University of Wisconsin, Madison, WI, United States

Routine monitoring of renal function following transplantation is important for prolonging allograft viability. In this study, BOLD MRI was used to measure renal oxygenation in matched donor-recipient pairs up to one year post-transplantation. An 11 % reduction of R2* was observed in the medulla of transplanted kidneys 3 months post-transplantation (p < 0.01), indicating increased oxygen availability. The cortex of the transplanted kidney and the donors’ remaining kidneys showed no change of R2* after 3 months. Additional measurements in this ongoing study will be used to assess oxygenation one and two years post-transplantation.

824.   in vivo T1lower case Greek rho Study on Human Kidney 
Xiang He1, Chan-Hong Moon1, Jung-Hwan Kim1, and Kyongtae Ty Bae1
1Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States

In this study, we improved the T1ρ sequence to compensate for both B0 and B1 field imperfections and applied this technique in the first time for T1ρ-weighted imaging and T1ρ mapping of in vivo human kidneys. Our result demonstrated that T1ρ signal of the kidney may provide additional information regarding the underlying structure of the kidney beyond the traditional T1, T2 and T2* measurement, and may serve as an important imaging biomarker for quantitative functional MRI of kidney. Additionally, the sensitivity of T1ρ to tissue compositions and interactions may broaden our understanding and detection of renal pathologies.

825.   Quantification of Renal T1 using a Modified Respiratory Triggered Inversion Recovery TrueFISP Scheme 
Eleanor F Cox1, Caroline L Hoad1, and Susan T Francis1
1SPMMRC, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

Quantification of T1 in the kidneys is subject to breathing induced movement between acquisitions of differing contrast. Here we use a modified respiratory triggered inversion recovery TrueFISP acquisition to measure T1 in the kidneys, requiring no breath hold or registration techniques. The mean T1 was 950 ± 40 ms in the renal cortex and 1210 ± 60 ms in the medulla. High resolution T1 maps show differentiation in T1 between the renal cortex and outer and inner medulla that could not be resolved at lower resolution.

826.   Study of Kidney SWI under Oxygenation Variation after Water Uptake - Initial Results 
Moritz Bernhard Mie1, Frank Gerrit Zoellner1, and Lothar Rudi Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany

Susceptibility weighted imaging (SWI) is not only a valuable tool for brain imaging, but also for renal imaging. In this study, the sensitivity of SWI to kidney-function induced changes of blood flow is investigated. Because the blood oxygenation level dependent (BOLD) contrast of blood depends on the local blood flow, the SWI contrast has been investigated while the kidney function has been increased. SWI has been applied before and after water uptake. In healthy volunteers, the SWI contrast decreases after water uptake and then increases again to the equilibrium value of the resting state.

827.   23Na MRI of the human kidney at 3T: Improving image quality by different image filters 
Frank G Zoellner1, Holger Best1, Simon Konstandin1, Stefan Haneder2, Stefan O Schoenberg2, Henrik J Michaely2, and Lothar R Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

One main purpose of the human kidneys is the maintenance and the regulation of the fluid and electrolyte homeostasis. About 80% of the filtrated substances are sodium. The combination of relative low in-vivo concentration and MR sensitivity of 23Na compared to 1H results in relative low MR signal. A logical step forward is to enhance the images by applying post-processing filters. We compared the performance of different filters in sodium imaging of the human kidney at 3T. SNR before and after filtering sodium images obtain in 4 healthy volunteers is improved by a factor of 3.6 for the Fermi, 3.2 for the Hamming and 3.2 for the Gaussian filter.

828.   Non-invasive CEST-MRI Measurement of pH in the Human Kidneys using an Approved CT Contrast Agent 
Jochen Keupp1, Ivan Dimitrov2,3, Sander Langereis4, Osamu Togao3, Masaya Takahashi3, and A Dean Sherry3
1Philips Research Europe, Hamburg, Germany, 2Philips Healthcare, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States, 4Philips Research Europe, Eindhoven, Netherlands

Clinical MR techniques to report on local pH would be of high interest, because several pathologies are associated with pH changes like in renal diseases. Fortuitously, a clinically approved CT agent, Iopamidol, has been shown to have exchangeable protons that generate pH-dependent CEST (chemical exchange saturation transfer)-MRI contrast. It provides two proton pools, which allow a ratiometric pH measure independent from the local agent concentration, as recently demonstrated pre-clinically. In the present study it is shown, that Iopamidol can be used for in vivo human pH measurement in the renal pelvis using breathing triggered CEST-MRI on a clinical 3T scanner.

829.   MR phantom validation of adrenal adenoma signal intensity index normalization 
Cory R Wyatt1, Brian Dale2, Elmar Merkle1, James MacFall1, and Brian Soher1
1Radiology, Duke University, Durham, NC, United States, 2Siemens Medical Solutions, Inc., Morrisville, NC, United States

In-phase and-opposed phase chemical shift magnetic resonance imaging has been extensively used for differentiating between an adenoma and metastatic growth in the adrenal glands. However, due to the range of scan parameters used in these studies, the thresholds reported differ significantly. In this work, we present a method for normalizing signal intensity indices used to differentiate adrenal adenomas from metastases regardless of the clinical parameters used to acquire the IP/OP images. It was found that the method was able to correlate signal intensity index values to the true fat/water signal ratio for phantoms containing small amounts of fat.

830.   Fat Quantification of Adrenal Adenomas Using 3D 3-Point Dixon MR Imaging: Comparison with Conventional 2D Dual Echo Chemical Shift MR Imaging 
Tomohiro Namimoto1, Kosuke Morita2, Toshinori Hirai2, Shinichi Nakamura2, Seitaro Oda2, Daisuke Utsunomiya2, Yasuyuki Yamashita2, and Makoto Obara3
1Radiology, Kumamoto University, Kumamoto, Kumamoto, Japan, 2Kumamoto University, 3Philips Medical Systems

3D high resolution 3-point Dixon techniques offer an alternative to 2D gradient echo chemical shift imaging for fat quantification of adrenal masses with higher accuracy.

Traditional Posters : Body (Non-Cancer) Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Fetal & Female Pelvis

Wednesday May 11th
Exhibition Hall  13:30 - 15:30

831.   MR spectroscopy of endometrial cancer - initial results at 3T 
Geoff Charles-Edwards1,2, Robert Johnstone1, Sarah Natas1, and Audrey Jacques1
1Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom, 2King's College London, London, United Kingdom

Endometrial carcinoma is the most common gynaecological malignancy in Western countries. Conventional grading and staging by biopsy and imaging does not always correspond with the final histological grade determined post-hysterectomy. This results in some patients having less aggressive initial surgery, while others will have unnecessary extensive lymph node dissection. Consequently there is a need for additional information to improve preoperative assessment. This work describes some initial results from MR spectroscopy at 3T providing metabolic information about endometrial cancer that may aid in preoperative assessment of disease.

832.   Uterine fibroids: quantitative assessment of baseline T1, ADC and microvascular properties with T1w DCE-MRI 
Lucy Elizabeth Kershaw1, Yuexi Huang1, Hallie Taylor2,3, Elizabeth David2, Kullervo Hynynen1,4, Greg Stanisz1,4, and Laurent Milot2,3
1Imaging Research, Sunnybrook Research Institute, Toronto, Ontario, Canada, 2Radiology, Sunnybrook Research Institute, Toronto, Ontario, Canada, 3Medical Imaging, University of Toronto, Toronto, Ontario, Canada, 4Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

Uterine fibroids are benign masses affecting ~20% of women of reproductive age, resulting in poor quality of life due to pelvic pain and dysmenorrhea. The success of treatments such as high intensity focused ultrasound depends on the perfusion of the fibroid, therefore a baseline assessment of the fibroid properties is important in the selection of the most appropriate treatment on a case-by case basis. Although the appearance on T2w images has been documented, quantitative assessment of fibroid properties has been rare. In this study, ADC, T1 measurements and DCE-MRI parameters derived from two different models are presented.

833.   Improved T2-weighted Imaging of the Pelvis using T2-prepared Single-slab 3D TSE (SPACE) 
John P. Mugler, III1, Talissa A. Altes1, Wilhelm Horger2, and Berthold Kiefer2
1Radiology, University of Virginia, Charlottesville, VA, United States, 2Siemens Healthcare, Erlangen, Germany

An adiabatic T2-contrast preparation was implemented for T2-weighted (T2W) single-slab 3D-TSE (SPACE) imaging of the prostate and uterus, and the resulting contrast properties were compared to those for the standard SPACE method and conventional 2D TSE in five healthy subjects (2 males, 3 females). T2-prepared SPACE provided image contrast that was different than that for either conventional T2W 2D TSE or standard T2W SPACE, and, in particular, yielded improved contrast of structures within the prostate. This observation, coupled with the ability to reconstruct multiple image planes from high-resolution 3D acquisitions, suggests that T2-prepared SPACE warrants evaluation in subjects with disease.

834.   Normal Liver T2* Values in the Fetus 
Tammar Kushnir1, Chen Hoffmann1, Lisa Raviv-zilka1, Yishay Salem1, Eli Konen1, and Orly Goitein1
1Dept. of Diagnostic Imaging, MRI Unit, The Chaim Sheba Medical Center, Tel Hashomer, Israel

T2* multi-echo gradient echo is a robust validated non-invasive method for the accurate evaluation of tissue iron. Low T2* values serve as an early marker of iron deposition in the target organs. The purpose of this study was to use the method to evaluate the standard liver T2* value in healthy fetus. To our knowledge this is the first documentation of T2* values for fetus. In our small cohort, average liver T2* values at the third trimester were found to be 21.5 ± 6.3 ms (range 12.5 -30), shorter than those of normal adult subjects.

Traditional Posters : Body (Non-Cancer) Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Body Diffusion: Technique & Clinical Applications

Thursday May 12th
Exhibition Hall  13:30 - 15:30

835.   ADC Quantification of Continuously Moving Table Whole-Body Diffusion-Weighted Imaging 
Yeji Han1, Sandra Huff2, HyunWook Park1, and Ute Ludwig2
1Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Daejeon, Korea, Republic of, 2Medical Physics, University Hospital Freiburg, Freiburg, Germany

To overcome the difficulties of multistation whole-body DWI (wbDWI), the authors have proposed a continuously moving table (CMT) wbDWI method in the previous work. However, more aspects of the CMT-wbDWI have to be validated to utilize this method in a clinical setting. Thus, the influence of continuous table motion on diffusion data was examined in this study by calculating apparent diffusion coefficient (ADC) values using a spherical water phantom. The experimental results show that the general tendency of ADC changes is preserved in all cases.

836.   Quantification accuracy of ADC measurements from Whole-Body DWIBS 
Alan John Stone1,2, Jacinta E Browne3, Brian Lennon4, James F. Meaney1, and Andrew J Fagan1,5
1Centre for Advanced Medical Imaging (CAMI), St. James’s Hospital / Trinity College, University of Dublin, Ireland, 2Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff, United Kingdom, 3School of Physics, Dublin Institute of Technology, Dublin, Ireland, 4Dept. Medical Physics and Bioengineering, St. James’s Hospital, Dublin, Ireland, 5School of Medicine, Trinity College, University of Dublin, Ireland

The use of DWI techniques to categorise malignancy or therapy efficacy in tumours has led in recent years to the use of the DWIBS technique for ADC quantification. A comparative study of DWIBS with an accurate ADC measurement technique found no difference in mean ADC values measured by the two techniques in a moving phantom and when static. However, a noticeable spread in ADC values was noted, particularly in small tumours, which may be of significance when monitoring therapy efficacy where slight changes in tumour heterogeneity may be inferred from subtle changes in ADC histograms

837.   Correlation of Urinary Bladder Cancer with Stalk observed on 3-Tesla MRI with histopathological T Staging and cystoscopic findings: Comparison of Diffusion- and T2-weighted imaging in stalk detectability 
Yoshimitsu Ohgiya1, Jumpei Suyama1, Syouei Sai1, Masaaki Kawahara1, Jirou Munechika1, Makoto Saiki1, Noritaka Seino1, Masanori Hirose1, and Takehiko Gokan1
1Showa University School of Medicine, Tokyo, Japan

The purpose of this study was to correlate urinary bladder cancer having a stalk observed on 3-Tesla MRI with histopathological T staging and cystoscopic findings and to compare T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) in stalk detectability. All of tumors with a stalk on MRI were papillary tumors noted on cystscopy. Non-papillary tumors did not show stalks on MRI. Most of the bladder tumors with a stalk on 3-Tesla MR imaging were in T1 or lower pathologic stages. DWI had superior detectability in stalks of papillary bladder tumors to T2WI, particularly in tumors more than 10 mm.

838.   NdH/dT: A new quantitative measure for Diffusion Weighted Imaging based evaluation of abdominal tumor response to therapy 
Moti Freiman1, Stephan Voss2, and Simon K Warfield1
1Computational Radiology Laboratory, Dept. of Radiology, Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Dept. of Radiology, Children's Hospital, Harvard Medical School, Boston, MA, United States

Diffusion Weighted Imaging and the derived Apparent Diffusion Coefficient (ADC) map can be use to quantify abdominal tumor response to therapy. Current techniques use only the tumor region mean or median ADC value. However, the actual response is more complex due to inherent tumor heterogeneity. We present a new approach to quantify the tumor's response based on entire cumulative histogram analysis. Our approach provides a single number that encapsulates the overall diffusivity changes over time. Representative results on three cases show that our measure is comparable with the radiologist qualitative evaluation.

839.   Simultaneous Compensation of Respiratory and Cardiac Motion Effect on liver DWI 
Tetsuo Ogino1,2, Tomohiko Horie3, Hayato Takano4, Thomas Kwee5, Taro Takahara6,7, Marc Van Cauteren8, and Tosiaki Miyati9
1Healthcare division, Philips Electronics Japan, LTD, Minato-ku, Tokyo, Japan, 2Graduate School of Medical Sciences, Kanazawa University, Kanazawa-shi, Ishikawa-ken, Japan, 3Dept. of Radiology, Tokai Univiersity Hospital, Isehara-shi, Kanagawa, Japan, 4Dept. of Radiology, Tokai University Hospital, Isehara-shi, Kanagawa, Japan, 5Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 6Biomedical Engineering, Tokai University School of Engineering, Hiratsuka-shi, Kanagawa, Japan, 7Dept. of Radiology, UMC Utrecht, Utrecht, Netherlands,8Philips Healthcare, 9Department of Quantum Medical Technology, Kanazawa University, Kanazawa, Ishikawa, Japan

Cardiac and Respiratory motion affects image quality and ADC measurement on abdominal DWI. Combined method of “PPU” Peripheral Pulse Unit cardiac triggering and "TRON" Respiratory motion compensation on 3.0T DWI is demonstrated. Signal uniformity and ADC uniformity on whole liver is improved. Averaged among 5 healthy volunteers, ADC value ratio between left and right lobe of liver is reduced to 1.04 with PPU TRON from 1.5 with conventional Respiratory Triggering DWI. Average scan time among 5 volunteers was 3:48. PPU TRON enables more uniform image quality and reproducible ADC measurement in clinically feasible scan time.

840.   Comparison of Breath-hold versus Free-breathing versus Respiratory Triggered and Navigator Triggered Diffusion Weighted Imaging of the Liver 
Moritz Florian Kircher1,2, Alan Xu1, Anja C. Brau3, Martin Laufik1, Yuji Iwadate4, Jarrett Rosenberg1, Bruce L Daniel1, and Robert J Herfkens1
1Radiology, Stanford University, Stanford, CA, United States, 2Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 3Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 4Global Applied Science Laboratory, GE Healthcare, Hino, Japan

Diffusion-weighted imaging (DWI) has become a routine part of abdominal MRI examinations at many institutions. Several different DWI techniques are currently in use, including breath-hold DWI and non-breathhold DWI techniques such as free-breathing, respiratory-triggered DWI and Navigator-triggered DWI. In this study, we aimed to prospectively evaluate and compare the subjective image quality of these four commonly used DWI techniques in 30 patients with liver lesions. The results demonstrate superiority of navigator-triggered and respiratory-triggered DWI over breath-hold and free-breathing DWI for most image quality parameters.

841.   Comparison of Breath-Hold and Free-Breathing Diffusion-Weighted Techniques for Liver MR Diffusivity in Healthy Volunteers and Patients 
Mamak Eatesam1, Susam M Noworolski1,2, Phyllis C Tien3, Michelle Nystrom1, Jennifer L Dodge4, Raphael B Merriman5, and Aliya Qayyum1
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Graduate Group in Bioengineering, UC San Francisco and Berkeley, San Francisco and Berkeley, CA, United States,3Department of Medicine, UCSF and San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States, 4Department of Internal Medicine, UCSF, Fresno, CA, United States,5Department of Medicine, California Pacific Medical Center, San Francisco, CA, United States

Liver apparent diffusion coefficient (ADC) values were compared between breath-hold and free-breathing DWI in 12 healthy volunteers and 16 patients, (9 NAFLDs and 7 HCVs). BH ADC was lower than FB ADC, (p<0.01). BH and FB liver ADC showed a moderate correlation at best such that BH and FB techniques should not be used interchangeably. A higher correlation between FB and BH was observed in NAFLD patients which may reflect differences in disease distribution or reduced range of respiratory effort in NAFLD patients due to a higher BMI.

842.   Diffusion-weighted MRI of the liver at 3T MRI: Effect of steatosis on ADC at low and high b values 
Andrew James Gilman1, Susan Moyher Noworolski1, Mamak Eatesam1, Jennifer Lynne Dodge1, Raphael Brendan Merriman2, and Aliya Qayyum1
1Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Division of Gastroenterology, California Pacific Medical Center, San Francisco, CA, United States

The relationship between liver ADC and steatosis was evaluated for high (125, 500), low (0, 125), and conventional (0, 500) b-value DWI at 3T in 6 healthy volunteers and 12 patients with NAFLD or HCV. Subjects with steatosis grade 1 or 2 (n=5) had significantly lower high b-value ADC compared to those with grade 0 (n=13) for both large (0.88 versus 1.09, p<0.04) and small (0.82 versus 1.12, p<0.02) ROIs. The effect of steatosis on liver ADC should be taken into account when using DWI to discriminate between features of diffuse liver disease.

843.   Reliability Analysis of Liver Apparent Diffusion Coefficient Measurement: Importance of ROI Size and Image Threshold 
Mamak Eatesam1, Michelle Nystrom1, Susan M Noworolski1,2, Jennifer L Dodge3, Raphael B Merriman4, and Aliya Qayyum1
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Graduate Group in Bioengineering, UC San Francisco and Berkeley, San Francisco and Berkeley, CA, United States,3Department of Internal Medicine, UCSF, Fresno, CA, United States, 4Department of Medicine, California Pacific Medical Center, San Francisco, CA, United States

The repeatability of liver ADC measurement was compared across different image analysis techniques designed to reduce the impact of vessels on the ADC. Two successive breath-hold DWI scans were performed in 14 subjects; 6 NAFLD and 8 healthy volunteers. ADC was derived from 6 small and 3 large ROIs and with 4 different image threshold applications. Results indicated that large ROI ADC measurements were more repeatable than small ROI measurements. Vessel correction was associated with the narrowest range of ADC difference between scans, suggestive of highest repeatability.

844.   Icewater for Quality Control of Diffusion Measurements in Multi-Center Trials 
Thomas L. Chenevert1, Craig J. Galbán1, Frank J. Londy1, Charles R. Meyer1, Timothy D. Johnson2, Alnawaz Rehemtulla3, and Brian D. Ross1
1Radiology - MRI, University of Michigan, Ann Arbor, Michigan, United States, 2Biostatistics, University of Michigan, Ann Arbor, Michigan, United States, 3Radiation Oncology, University of Michigan, Ann Arbor, Michigan, United States

Prerequisites for use of ADC, as well as any image-based biomarker in multi-center trials is standardization of data acquisition/analysis, and certification of sites/systems via quantitative measurements on known test objects. The objective of this study is to assess reproducibility of ADC measurements performed at multiple sites on various clinical platforms using icewater as a simple universal temperature-controlled diffusing medium. In this study system outlier(s) were identified, and 3-5% reproducibility in diffusion coefficient measurement exclusive of outliers was demonstrated. Systematic spatial-dependent error was also demonstrated with its source under investigation.

845.   Monitoring acellular matrix-based soft tissue regeneration: multiexponential diffusion and T2* for improved specificity 
Hai-Ling Margaret Cheng1,2, Yasir Loai2, and Walid A Farhat2
1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, 2Hospital for Sick Children, Toronto, Ontario, Canada

Quantitative MRI parameters such as T1 and T2 relaxation times provide a means to probe tissue microstructure and composition. However, specificity is often limited, as is the case when interrogating complex systems such as regenerating tissue where concurrent biophysical and biochemical changes exist. This study explores multiexponential diffusion and effective transverse relaxation time T2* at 1.5 Tesla for probing cell growth and tissue composition. The slow diffusion fraction from multiexponential diffusion analysis yielded the best correlation with cellularity, with minimal influence from underlying matrix degradation. T2* measurements were sensitive to macromolecular content without confounding influence from tissue hydration.

846.   Efficient EPI distortion correction using non-phase encoded reference data 
Anne-Sophie Glantenay1, Chiel J Den Harder1, Johan S Van Den Brink1, Gwenael Herigault2, and Jos Koonen3
1Advanced Development, Philips Healthcare, Best, Netherlands, 2MR Cliniclal Science, Philips Healthcare, Best, Netherlands, 3MR Development, Philips Healthcare, Best, Netherlands

Diffusion-weighted EPI has become an indispensable tool in body MRI. However geometric distortions due to field inhomogeneities may hamper comparison of the diffusion images with T2W_TSE images. Here we implement and evaluate an efficient geometry correction method based on the non phase–encoded EPI reference acquisition used for Nyquist ghost removal. The method provides accurate and robust global geometry correction in the absence of strong, local phase offsets. It does not require additional time for calibrations, and is directly compatible with parallel imaging methods.

Traditional Posters : Body (Non-Cancer) Imaging
Click on to view the abstract pdf and click on to view the pdf of the poster viewable in the poster hall.
Body Fat & Body MRS

Monday May 9th
Exhibition Hall  14:00 - 16:00

847.   Fully automated measurement of total adipose tissue volume using quantitative chemical shift MRI: Phantom Validation 
Aziz H Poonawalla1, Catherine DG Hines1, Diego Hernando1, Pablo Irarrazaval1,2, and Scott Brian Reeder1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Biomedical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile

Fully-automated measurement of total adipose tissue using quantitative chemical shift MRI is demonstrated using a quantitative volumetric chemical-shift fat/water imaging method in phantoms. Fat, water and quantitative fat-fraction images were acquired at 3T with a 32-channel phased array in 26 sec of a series of peanut oil-filled phantoms of known volume and increasing surface area via inclusion of agar balls, glass rods, and empty vials. Robust fat volumes were measured in excellent agreement (r2 = 0.99) with known volumes of oil, with no user intervention, and immunity to partial volume effects.

848.   Software for fully automatic quantification of abdominal fat with manual correction option 
Henriette Bertram1, Gregor Thörmer1, Florian Dazinger1, Matthias Raschpichler1, Nikita Garnov1, Thomas Kahn1, Matthias Blüher2, and Harald Busse1
1Department of Diagnostic and Interventional Radiology, University Hospital of Leipzig, Leipzig, Saxony, Germany, 2Department of Endocrinology and Nephrology, University Hospital of Leipzig, Leipzig, Saxony, Germany

Abdominal fat is associated with an increased risk for various diseases and can be quantified with MRI. Manual segmentation of subcutaneous (SAT) and visceral adipose tissue (VAT) is time consuming while automatic analyses are prone to errors. Therefore, an automatic technique with manual correction option was developed. Good agreement was observed between two readers for manual VAT and SAT quantification in 10 obese patients. Automatic volumes were 17±8% (VAT, p<0.001) and 1±3% (SAT, p=0.397) higher than the manually derived. These preliminary results suggest that the combined approach holds great promise for a fast (6 min) and sufficiently accurate fat quantification.

849.   General Methodology for Accurate MRI Abdominal Adipose Tissue Quantification 
Anqi Zhou1, Horacio Murillo1, and Qi Peng1
1Radiology, UT Health Science Center at San Antonio, San Antonio, TX, United States

Fast and accurate abdominal fat quantification has been more challenging on non-water-saturated (NWS) than on water-saturated (WS) MR images. We propose a general approach based on a combination of fuzzy c-means (FCM) clustering and signal intensity thresholding. The novel FCM algorithm utilizes the signal intensity of the neighboring voxels in addition to that of each voxel to eliminate full-volume water voxels from the original image. Statistically consistent results were obtained when the same algorithm was applied to both WS and NWS MR images. It is therefore a general approach to non-subjective, reproducible abdominal fat quantification on MR images.

850.   Visceral fat saturation is positively correlated with liver fat content 
Jesper Lundbom1, Antti Hakkarainen2, Sanni Söderlund3, Jukka Westerbacka3, Nina Lundbom1, and Marja-Riitta Taskinen3
1HUS Medical Imaging Center, Helsinki, Finland, 2HUS Medical Imaging Center, 3Department of Medicine, Helsinki University

We used long TE 1H-MRS to characterize visceral adipose tissue saturated fat. The CH2/CH3 ratio correlated positively with liver fat content in 14 male subjects. This is in contrast to a previously reported negative correlation between subcutaneous CH2/CH3 and liver fat content.

851.   Rapid, volumetric segmentation of visceral adipose tissue with quantitative chemical shift MRI at 3T 
Aziz H Poonawalla1, Brett P Sjoberg1, Michael Schroeder1, Diego Hernando1, Pablo Irarrazaval1,2, and Scott Brian Reeder1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Biomedical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile

Quantitative measurement of visceral adipose tissue (VAT) is demonstrated using a volumetric chemical-shift fat/water imaging method with corrections for relaxation effects and accurate spectral modeling of fat. Fat, water and quantitative fat-fraction images were acquired over the entire abdomen and pelvis at 3T with a 32-channel phased array in a single 26-sec breath-hold. Robust VAT volumes were measured semi-automatically with <30 min post-processing, with strong correlation (r2 = 0.99) to manually-segmented VAT requiring ~4 hours.

852.   Observation of TCA cycle metabolism in human liver by dynamic 13C-MRS 
Douglas E Befroy1,2, Kitt Falk Petersen2, Peter B Brown1, Douglas L Rothman1,3, and Gerald I Shulman2,4
1Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, 2Internal Medicine, Yale University School of Medicine, New Haven, CT, United States, 3Biomedical Engineering, Yale University School of Medicine, New Haven, CT, United States, 4Howard Hughes Medical Institute, New Haven, CT, United States

Monitoring liver TCA cycle metabolism in vivo using classic 13C labeling strategies (infusing 1-13C glucose or 2-13C acetate) is unfeasible since intrahepatic lipid obscures the detection of C4-glutamate enrichment. Recently, alternative labeling schemes have been demonstrated in brain whereby enrichment at C5-glutamate, which resonates in a region free from overlapping lipid peaks, was monitored following the infusion of 2-13C glucose or 1-13C acetate. By adopting this strategy, we established that C5-glutamate enrichment can be detected in human liver without interference from intracellular lipid and observed hepatic substrate oxidation via the TCA cycle for the first time.

853.   13C-labelling and non-invasive detection of glutathione in human liver 
Peter Edward Thelwall1, Fiona Elizabeth Smith1, Matthew Clemence2, Kieren G Hollingsworth1, Roy Taylor1, and Michael P Gamcsik3
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, 2Philips Healthcare - Clinical Science, Guildford, United Kingdom, 3Joint Department of Biomedical Engineering, University of North Carolina / NC State University, United States

Glutathione is a tripeptide that is a central component of cellular defences against oxidative stress. We have shown that a 13C label can be introduced into glutathione in humans by oral administration of [2-13C]-glycine, where this amino acid is incorporated into glutathione. We have shown that 13C-labelled glutathione can be detected by 1H-decoupled 13C spectroscopy in human liver, allowing measurements of glutathione concentration and synthesis rate and providing an insight into cellular defences against oxidative stress.

854.   Assessment of liver fat using magnetic resonance spectroscopic imaging (MRSI) 
Shing-Ru Chen1, Yi-Ru Lin2, Posse Stefan3,4, and Shang-Yueh Tsai5
1Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 2Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 3Department of Neurology, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States, 4Department of Electrical And Computer Engineering, University of New Mexico, Albuquerque, New Mexico, United States, 5Department of Electrical Engineering, Chang Gung University, Taoyuan, Taiwan

Fatty liver as a common disease in modern life can be associated with a variety of disorders. Quantification of liver fat content relies on liver biopsy. Recently it has been shown that MRS can be used as an alternative method to measure liver fat. In this preliminary report, proton echo-planar spectroscopic imaging (PEPSI) is proposed to quantify spatial distribution of fat content in liver. Feasibility and reproducibility of liver MRSI were investigated. Results showed that PEPSI is able to detect liver fat content within short acquisition time. And the measured lipid fat fraction is highly reproducible.

855.   In vivo Characterization of Liver Fat Composition by 1H MR Spectroscopy 
Gavin Hamilton1, Michael S Middleton1, Takeshi Yokoo1, Lisa G Clark1, and Claude B Sirlin1
1Department of Radiology, University of California, San Diego, San Diego, California, United States

We examine the repeatability of liver triglyceride characterization by 1H MR Spectroscopy using a theoretical triglyceride model. Estimates of triglyceride unsaturation obtained from 1H MRS respiratory gated and free breathing acquisitions were compared. 1H MR Spectroscopy can repeatably measure the degree of liver fat unsaturation, and spectra collected with respiratory gating give a more repeatable characterization of liver fat composition than spectra collected with free breathing.

856.   Serial 1H magnetic resonance spectroscopy detects liver steatosis associated with chemotherapy in advanced colorectal cancer patients 
Kristen Zakian1, Jing Qi1, Lawrence Schwartz2, Yuman Fong3, Leonard Saltz4, Nancy Kemeny4, Michael D'Angelica3, William Jarnagin3, and Jason Koutcher1
1Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 2Radiology, Columbia University Medical School, 3Surgery, Memorial Sloan-Kettering Cancer Center,4Medicine, Memorial Sloan-Kettering Cancer Center

Liver toxicity related to chemotherapy is a growing concern in the combination use of chemo agents. To evaluate the chemotherapy related liver steatosis, serial 1H MRS was applied to monitor hepatic triglyceride contents changes in 27 colorectal cancer patients during FOLFOX or FUDR/irinotecan treatment. Fat/fat+water ratio (FFW) measured from baseline and post treatment were compared in 17 patients who finished 12 cycle chemotherapy. 9 patients showed increased FFW greater than 15% compared to baseline, indicating chemotherapy associated steatosis. Serial1H-MRS quantitatively evaluates the mobilization of liver fat, providing a more accurate way to detect chemo-associated steatosis.

857.   1H MRS methodology, dietary effects and impact of surgical stress on hepatic lipids in NAFLD animal models 
Jan-Bernd Hövener1, Uta Dahmen2, Bernd Merkel3, Olaf Dirsch4, Jürgen Hennig1, and Dominik von Elverfeldt1
1Department of Radiology, Medical Physics, University Medical Center, Freiburg, Germany, 2Experimentelle Transplantationschirurgie, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie, Jena, Germany, 3Fraunhofer MEVIS, Germany, 4Institut für Pathologie, Jena, Germany


858.   Reproducibility and diagnostic accuracy of in vivo proton magnetic resonance spectroscopy in detection of hepatic steatosis 
Jing Qi1, Mithat Gönen2, Jinru Shia3, Lawrence Schwartz4, Nancy Kemeny5, Michael D'Angelica6, Yuman Fong6, Jason Koutcher1, and Kristen Zakian1
1Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 2Epidemiology-Biostatistics, Memorial Sloan-Kettering Cancer Center, 3Pathology, Memorial Sloan-Kettering Cancer Center, 4Radiology, Columbia University Medical School, 5Medicine, Memorial Sloan-Kettering Cancer Center, 6Surgery, Memorial Sloan-Kettering Cancer Center

To assess the reproducibility of hepatocellular triglyceride content measurements on a 1.5T scanner using 1H MRS during a single breath-hold, 16 heathy adults were studied twice with a 2 week interval. The intra- and inter- examination coefficients of variance were 6% and 15% respectively. To evaluate the accuracy of 1H MRS in quantitation of HTGC, fat/(fat+water) (FFW) from 16 colorectal cancer patients was correlated with liver histology. A positive correlation (r = 0.78, P < 0.001) was observed between FFW and histology steatosis grade. A FFW cutoff value of 0.025 results in 86% sensitivity and 89% specificity for detection of clinically relevant steatosis.

859.   Assessment of hepatic lipid content by MRS in patients on home parenteral nutrition 
Marinette van der Graaf1,2, and Geert J Wanten3
1Clinical Physics Lab of Dept of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, 2Dept of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 3Dept of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands

Patients with severe intestinal problems who receive Home Parenteral Nutrition (HPN) are at risk for developing hepatic dysfunctioning due to steatosis. In the present study, hepatic lipid content was determined by MRS in 13 patients on HPN. To allow for correction for T2 relaxation, single voxel STEAM measurements were performed at 3T using multiple echo times. Five patients had high hepatic lipid contents (12.8%±3.5%, mean±SD), while the other eight had normal liver fat concentration (1.1%±0.6%). In addition, most patients showed increased T2 relaxation behavior probably due to elevated hepatic iron or manganese content.

860.   Fatty Liver Disease in Overweight Adolescent Girls Measured with Quantitative MRI and MR Spectroscopy 
Jennifer Leigh Rehm1, Vanessa A Curtis1, Catherine DG Hines2, Ellen L Connor1, Aaron L Carrel1, David B Allen1, and Scott B Reeder2,3
1Pediatrics, University of Wisconsin Hospital and Clinics, Madison, WI, United States, 2Radiology, University of Wisconsin Hospital and Clinics, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin Hospital and Clinics, Madison, WI, United States

Non-alcoholic fatty liver disease is a growing problem in the pediatric population and is anticipated to be the leading cause of liver failure in the future. Traditional methods of detecting fatty liver, such as ultrasound or liver enzyme blood screening, are insensitive to early stages of disease. We have demonstrated the feasibility of a rapid, clinically relevant, non-invasive method for early detection and quantitative staging of hepatic steatosis. While hepatic steatosis does correlate with elevated ALT, it is only moderately correlated with traditional markers of metabolic risk such as insulin resistance and hyper-triglyceridemia, and does not correlate with BMI. We have demonstrated that a novel quantitative MRI fat-fraction technique holds promise as a method for early detection, staging and treatment monitoring of NAFLD in obese adolescents.

861.   In vivo liver 31P MRS at 7T: Initial experience 
Marek Chmelik1, Stephan Gruber1, Siegfried Trattnig1, and Wolfgang Bogner1
1MR Centre of Excellence, Department of Radiology, Medical University Vienna, Vienna, Austria

The feasibility of hepatic in vivo localized 31P-MRS at 7T in clinically acceptable measurement time was tested using three different localization strategies (1D-ISIS, 3D-ISIS and hybrid 1D-ISIS/2D-CSI). The quality of acquired spectra was compared in terms of SNR, linewidths and PCr contamination from surrounding muscle. Liver 31P MRS at 7T provides improved data quality in acceptable measurement time. 3D-ISIS and 1D-ISIS/2D-CSI provide excellent localization whereas 1D-ISIS provides highest SNR in shortest time but higher contamination.

862.   Comparison of in vivo hepatic localized proton magnetic resonance spectroscopy at 9.4T on ob/ob and ob/+ mice 
Qiong Ye1, Alexander Fuchs1, and Markus Rudin1,2
1University and ETH Zürich, Institute for Biomedical Engineering, Zürich, 8093, Switzerland, 2University of Zürich, Institute of Pharmacology and Toxicology, Zürich, Switzerland

Both hepatic lipids amount and their composition were accessed non-invasively with proton magnetic resonance spectroscopy on ob/ob, a well-established murine model of obesity, and their heterozygous ob/+ mice at 9.4T. In this work, the results from both ob/ob and ob/+ mice were compared. From the results, ob/ob mice showed significant higher hepatic lipid amount than ob/+ mice. Hepatic lipid from ob/ob mice were characterized with much more saturated components and longer molecular chain length. But no significant difference was obtained in the total unsaturated index, polyunsaturated bond index and total unsaturated bond index at the age of 24 weeks.

863.   Hepatic fatty acid quantification using MRS and GC in a mouse model of GSD1A under two different diets 
Nirilanto Ramamonjisoa1, Helene Ratiney1, Elodie Mutel2, Herve Guillou3, Gilles Mithieux2, Frank Pilleul1,4, Fabienne Rajas2, Olivier Beuf1, and Sophie Cavassila1
1CREATIS, CNRS UMR 5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Université de Lyon, Lyon, France, 2Inserm U855, Université Lyon 1, Université de Lyon, France, 3INRA ToxAlim – Integrative Toxicology & Metabolism, Toulouse, France, 4Imagerie Digestive - CHU, Hospices Civils de Lyon, France

Glycogen storage disease type I (GSD1) is an autosomal recessive metabolic disorder resulting in severe impairment of glucose production and large accumulation of liver fatty acids. In this paper, short-TE in vivo MRS and gas chromatography (GC) analysis were used to evaluate the fatty liver content and the fat fraction composition in the mouse model of GSD1a under two different diets, a chow and a high fat high sucrose diet. Strong agreements between the quantitative lipid profiles measured by MRS and GC were demonstrated. Our results confirm that 1H MRS is a suitable non invasive tool for hepatic lipid quantification and lipid fraction estimation.

864.   Glucose and Intralipid Infusion in Rats: Comparative Quantification of Liver Steatosis by MRI, MRS and Histopathology 
Gaspard d'Assignies1,2, Ghislaine Fontés3,4, Louis Gaboury5, Yvan Boulanger6,7, Gilles Soulez3, Vincent Poitout3,4, and An Tang8
1Department of Medical Imaging, Hôpital Saint-Luc, Montreal, Quebec, Canada, 2Department of Radiology, Beaujon Hospital, Université Paris VII, Paris, France, 3CRCHUM, Canada, 4Montréal Diabetes Research Center, Canada, 5CHUM, Canada, 6Hôpital Saint-Luc, University of Montreal, 7CRCHUM, 8Department of Medical Imaging, CRCHUM, Montreal, Quebec, Canada

This study compares quantification of liver steatosis by MRI and histopathology by using MRS as the reference standard for the discrimination of three rat phenotypes assigned to an experimental glucolipotoxic steatosis model or a control group. A significant correlation was found between dual-echo MRI and MRS. A weaker correlation was found between histopathology and MRS. MRI and MRS accurately distinguished the rats receiving the infusion of glucose + Intralipid from those receiving the saline control, whereas histology did not. Although many authors use histopathology as the gold standard, vacuolar degeneration and glycogen may limit its accuracy for liver fat quantification.

865.   Properties of brown and white adipose tissues measured by 1H MRS 
Gavin Hamilton1, Daniel L Smith2, Mark Bydder1, Krishna S Nayak3, and Houchun H Hu3
1Department of Radiology, University of California, San Diego, San Diego, California, United States, 2Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States, 3Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California, United States

We explored the MR signatures of brown adipose tissue (BAT) compared to white adipose tissue (WAT) using single-voxel STEAM 1H MR spectroscopy on a 3 Tesla clinical whole body scanner from excised murine adipose tissue samples. Spectra were acquired at multiple TEs and TIs to measure the T1, T2, and T2-corrected individual fat and water peak areas. A theoretical triglyceride model characterized the multi-peak fat spectra. The water fraction in BAT was higher compared to WAT and the T1 of water was lower in BAT compared to WAT. BAT also contained lower levels of unsaturated triglycerides in comparison to WAT.

866.   In Vivo 1H/13C MR Analysis Reveals Visceral Obesity, Hepatic Steatosis, and Disorders in Body Fat Composition Upon Long-Term Medium Chain Triglyceride Diet in Mice With a Defect in Fatty Acid Oxidation 
Ulrich Flögel1, Sara Tucci2, Jürgen Schrader1, and Ute Spiekerkoetter2
1Institute for Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, NRW, Germany, 2Department of General Pediatrics

Therapeutical approaches to limit metabolic derangement in patients with long chain fatty acid oxidation disorders (LCAD) include fat-modified diets, in which long-chain triglycerides are replaced by medium-chain triglycerides (MCT). The present study investigated the effects of a long-term MCT therapy on body lipid homeostasis using 1H MRI and 1H/13C MRS in a murine model of LCAD. One year MCT-based diet resulted in massive visceral fat infiltration, impaired body fat composition, and steatohepatitis. Although MCT diet has been reported to prevent development of cardiomyopathy and the myopathic phenotype, according to our data its use and dose has to be well considered.

867.   Changes in body tissue composition during the Transeuropean Footrace 2009 assessed by whole-body MRI in 12 Finishers 
Jürgen Machann1, Christian Billich2, Kathrin König1, Christian Würslin1, Fritz Schick1, and Uwe Schütz2
1Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany, 2Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Germany

Twelve endurance athletes underwent follow-up MR examinations during the Transeuropean Footrace 2009 from Bari to the North Cape on a mobile MR-scanner for determination of whole-body tissue composition. A T1-weighted TSE sequence was applied and different adipose tissue (AT) compartments as well as muscle mass in lower and upper extremities were quantified and analyzed. All AT compartments showed a strong reduction during the race with the strongest decline for visceral AT (-70% compared to baseline). Muscle mass of lower extremities was also reduced. Comparison of these MRI-findings with biometrical data and laboratory findings will present further details regarding tissue metabolism and energy balance during long distance running.

868.   Evaluation of high fat diet induced obesity in rats by longitudinal MRI and MRS in abdomen, liver and skeletal muscle 
Arunima Pola1, Sandra Tan2, Terry Yew Shze Keong1, Zhihong Zhou2, Mika Murabayashi3, Yoshihide Nakano3, Naoki Furuyama3, Nicholas Hird3, and Sendhil Sambashivam Velan1
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, 2Takeda Singapore Pte Ltd, Singapore, 3Takeda Pharmaceutical Company Ltd, Japan

Obesity is a medical condition in which excess body fat accumulates in areas such as abdomen, liver and skeletal muscle. In this study, experimental rodent models of obesity were used to investigate fat accumulation in these organs by longitudinal in vivo MRS/MRI measurements. Fat estimation in the abdomen was based on axial image segmentation. Spectral analysis by LCModel was used for fat calculation in liver and skeletal muscle. All our measurements are correlated with body weight, food intake and blood chemistry. The results demonstrate that MRI/MRS approach can be used to evaluate the potential of novel drugs in rodent models of obesity and diabetes.

869.   1H MRS of Pancreatic Juice: An MRS-based Diagnostic Approach for the Detection of Pancreatic Cancer 
Tedros Bezabeh1, Omkar B Ijare1, Nils Albiin2, Matthias Lohr2, Annika Bergquist2, Urban Arnelo2, and Ian C.P. Smith1
1National Research Council Institute for Biodiagnostics, Winnipeg, MB, Canada, 2Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden

Pancreatic cancer is the fourth most common cause of cancer-related deaths with a very low overall 5-year survival rate (<5%). Proteomics-based analyses have detected molecular alterations (K-ras mutations, telomerase reactivation, or methylation of the tumor-suppressor genes) in pancreatic juice samples obtained from patients with pancreatic cancer. However, no definitive molecular markers have been identified yet for the diagnosis of pancreatic cancer. In this study, we have performed 1H-MRS-based biochemical analysis of pancreatic juice samples from different pancreatic diseases including adenocarcinoma. Such analysis will serve as a basis for a metabolomics-based diagnostic approach for the detection of pancreatic cancer.

870.   In vivo 1H MRS of human Gallbladder Bile using an Optimized 16-Channel Phased Array at 3T 
Sanaz Mohajeri1,2, Tedros Bezabeh1, Scott B. King1, Omkar B. Ijare1, M. A. Thomas3, Gerald Minuk2, Jeremy Lipschitz2, Iain Kirkpatrick2, and Ian CP. Smith1
1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada, 2University of Manitoba, Winnipeg, Manitoba, Canada, 3University of California, Los Angeles, California, United States

Magnetic Resonance Spectroscopy (MRS) is a method useful for the detection of mobile molecular species in a sample that have diagnostic utility. In vitro 1H MRS of human bile samples has been successful in detecting various hepatopancreatobiliary disorders. Therefore, there is a great interest in performing such analysis in vivo. We performed 1-D and 2-D 1H MRS of human gallbladder bile using a 3T clinical scanner and an optimized home-built receive array coil. Our preliminary efforts in obtaining good quality spectra are promising.

871.   Spectroscopic Water-Fat Quantification in Human Kidney at 3T 
Qing Yuan1, Ivan Dimitrov2, Naim M Maalouf3, Khashayar Sakhaee3, and Paul T Weatherall1
1Radiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States, 2Philips Medical Systems, Cleveland, Ohio, United States, 3Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States

Noninvasive measurement of renal cortical fat content can potentially determine the degree of renal fat accumulation in various kidney disorders. The goal of this study was to develop a technique to perform in vivo 1H MRS in human kidney at 3T and to establish nominal values of fat content in normal volunteers. A respiratory-triggered non-water suppressed single-voxel PRESS sequence with TE-averaging was used to reduce motion and sideband artifacts. No fat content was detected from kidney parenchyma in healthy subjects. Voxel placement was crucial since including perirenal or hilar fat within the kidney resulted in fat contamination of the spectra.

872.   1.5T and 7T MR Spectroscopy of Tissue Specific Changes in Ectopic Fat Content in Response to Exercise Training in Type 2 Diabetes Mellitus Patients: The ATLAS-study 
Jacqueline T. Jonker1, Ralph L. Widya2, Sebastiaan Hammer2, Linda D. van Schinkel1, Rutger W. van der Meer2, Eelco J.P. de Koning3, Henk J.G. Bilo4, Andrew Webb2, Hermien E. Kan2, and Hildo J. Lamb2
1Endocrinology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 2Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 3Nephrology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 4Internal medicine, Isala klinieken (Sophia), Zwolle, Netherlands

Ectopic fat accumulation in type 2 diabetes is associated with insulin resistance and increased risk for cardiovascular disease. Although changes in diet have beneficial effects on ectopic fat accumulation, this is less clear for effects of exercise training. The purpose of the present study was to assess effects of a 7-month exercise program on ectopic fat accumulation in heart, liver and skeletal muscle measured by 1H-MRS at 1.5T and 7T. 7-month exercise decreases hepatic TG content. Myocardial and myocellular lipid content remained unchanged. Therefore, exercise intervention in patients with type 2 diabetes mellitus induces tissue-specific changes in ectopic fat distribution.