Breast MR

Hall B                        Tuesday 13:30-15:30                                                                                                 

                  2469.     High Resolution MR Imaging and Spectroscopy of the Human Breast at 7T Using a Focused Field RF Coil Setup

Dennis WJ Klomp1, Alexander Raaijmakers2, Mies Korteweg1, Bart van de Bank1, Cecilia Possanzini3, Vincent Boer1, Fredy Visser3, Nico van de Berg2, Peter Luijten1

1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands; 3Philips Health Care

MRI of the human breast at higher B0 fields, like 7T, can improve SNR, but may be restricted by non uniform excitation and restricted RF power deposition (SAR). Here we propose the use of a RF coil setup with focused field in the female breast to gain from the maximum sensitivity that can be obtained at 7T, illustrated by high resolution MRI and MRS in healthy subjects and patients.

                  2470.     Simple Approach for Increasing SNR, Reducing Breast Shading and Improving Fat Suppression at 3T

Ileana Hancu1, Laura Sacolick2, Seung-Kyun Lee1, W Thomas Dixon1, Randy Giaquinto1, Graeme McKinnon3, Vijayanand Alagappan4

1GE Global Research Center, Niskayuna, NY, United States; 2GE Global Research Center, Munich, Germany; 3GE Healthcare, Waukesha, WI, United States; 4GE Healthcare, Aurora, OH, United States

The main cause of the shading and improper fat suppression artifacts in breast imaging at 3T was identified as a bimodal distribution of the excitation field. A correction approach, based on the permanent placement of a passive loop tuned to 150MHz over the (always weaker) right side of a standard 8 channel breast receive array, was shown to mitigate the problem, result in more uniform B1transmit, better fat suppression and higher SNR, all with lower specific absorption rate.

                  2471.     Differentiation Between Intermingled and Central Type Breast Parenchymal Patterns Using Quantitative Morphological Parameters Based on Segmented Dense Tissue

Ke Nie1, Jeon-Hor Chen1,2, Daniel Chang1, Chieh-Chih Hsu2, Orhan Nalcioglu1, Min-Ying Lydia Su1

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

Breast parenchymal pattern is a well-known risk factor. The commonly used term ¡®breast density¡¯ only measures the amount of breast tissue, not the relative distribution between the fat and fibroglandular tissue. In this study, we developed quantitative parameters to characterize different parenchymal distribution patterns (intermingled vs. central types) based on the segmented dense tissue on 3D MRI. In a dataset of 230 cases, the area under the ROC curve could reach to 0.94 using combined parameters. These features can be further used to investigate the relationship between parenchymal pattern and the cancer risk.

                  2472.     Evaluation of Neoadjuvant Chemotherapy Response of Breast Cancer at 3.0T

Jeon-Hor Chen1,2, s Bahri1, P Carpenter3, H-J Yu1, R Mehta4, O Nalcioglu1, M-Y Lydia Su1

1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taichung, Taiwan; 3Department of Pathology, UC Irvine, Irvine, CA, United States; 4Department of Medicine, UC Irvine, Irvine, CA, United States

The results analyzed from 3.0 T were consistent with our previous findings using 1.5T with a lower spatial resolution, suggesting that the limitation of MRI in diagnosis of post-NAC cancer cannot be improved with a higher SNR or a higher spatial resolution. Our current protocol at 3.0 T still could not detect residual tumor presenting as scattered cells or small foci, which often occurs in non-mass-like lesions. These types of invasive cancer cells do not need angiogenesis to survive, and if so, they will not show contrast enhancements.

                  2473.     Reduction of Breast Density Following Tamoxifen Treatment Evaluated by 3-D MRI

Jeon-Hor Chen1,2, Yeun-Chung Chang3, Daniel Chang1, Yi-Ting Wang3, Ke Nie1, Ruey-Feng Chang3, orhang Nalcioglu1, Chiun-Sheng Huang3, M-Y Lydia Su1

1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taiwan; 3National Taiwan University, Taiwan

We have demonstrated that the breast density analyzed based on a 3D MR method can be used to investigate the changes associated with tamoxifen treatment. We found a significant reduction in fibroglandular tissue volume and percent breast density after treatment, and the density reduction was positively correlated with the baseline density and treatment duration.

                  2474.     MRI Evaluation of Decrease of Breast Density in the Contralateral Normal Breast of Patients Receiving Neoadjuvant Chemotherapy

Jeon-Hor Chen1,2, Ke Nie1, S Bahri1, Rita S. Mehta3, Chieh-Chih Hsu2, Fei-Ting Hsu2, Han-Ni Shih2, Muqing Lin1, orhang Nalcioglu1, M-Y Lydia Su1

1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taichung, Taiwan; 3Department of Medicine, UC Irvine, Irvine, CA, United States

We have demonstrated the feasibility of investigating the reduction of density following chemotherapy using a quantitative analysis method based on MRI. Patients receiving chemotherapy showed reduction of breast density, and that the effects were more pronounced in younger women than older (post-menopausal) women. The results suggest that the reduction of breast density after chemotherapy was possibly mediated through impaired ovarian function. The reduction could be clearly noted after 1 to 2 cycles of AC regimen. Although the density continued to decrease after 4 cycles of AC and the following Taxane regimen, the subsequent effect was smaller.

                  2475.     Pushing Old Boundaries in Breast MRI: Non-Fatsaturated Dynamic Imaging at Very Short TE

Christian Geppert1, Rolf Janka2, Berthold Kiefer1, Michael Uder2, Evelyn Wenkel2

1MR Oncology, Siemens Heatlthcare, Erlangen, Germany; 2Radiologisches Institut, Universitätsklinikum Erlangen, Erlangen, Germany

In non-fatsuppressed dynamic breast imaging, it is a well accepted recommendation to acquire data at or close to echo times that fulfil the in-phase condition for fat and water, such as 4.7ms at 1.5T, in order to avoid partial volume effects that lead to signal cancellation at fat/water interfaces. Thus it is usually suggested of using either in-phase TE or “TE less than 1.2ms” resulting in a phase difference of below 90°. In a comparable parameter setting this would result in a decrease of 50% of the total acquisition time. With current gradient systems and fast imaging sequences this has now become possible without compromising the matrix size or the bandwidth. In this work we have set up an interleaved protocol approach to achieve a direct comparison of a minimum TE acquisition with a clinical standard protocol.

                  2476.     Improved Diagnostic Accuracy in DCE MR-Mammography by Normalization of Kinetic Parameters Following AIF Deconvolution

Endre Grøvik1, Kjell-Inge Gjesdal2, Kathinka Kurz Dæhli3, Atle Bjørnerud4

1University of Oslo, Oslo, Norway; 2Sunnmøre MR-klinikk, Aalesund, Norway; 3Stavanger University Hospital, Stavanger, Norway; 4Rikshospitalet University Hospital, Oslo, Norway

This work presents a method for improving diagnostic accuracy in DCE MR-mammography by normalization of kinetic parameters following AIF deconvolution. The permeability related kinetic parameter Ktrans and the Ktrans-ratio between cancer tissue and breast parenchyma were investigated and compared based on their ability to differentiate between malignant and benign lesions. The result showed that employing a normalization approach may improve the diagnostically performance of the pharmacokinetic model by diminishing the prospective errors in the extracted AIF.

                  2477.     Influence of Contrast Arrival Time and Temporal Resolution in Diagnosis of Breast Cancer with DCE-MRI

Hendrik Laue1, Anja Hennemuth1, Volker Diehl1,2, Markus Thorsten Harz1, Horst Karl Hahn1, Heinz-Otto Peitgen1

1Fraunhofer MEVIS, Bremen, Germany; 2Institute of Magnetic Resonance Imaging, Central Hospital St.-Juergen-Strasse, Bremen, Germany

The consensus on diagnosis of breast cancer with DCE-MRI is the use of sequences with high spatial and low temporal resolution, because of the in inhomogeneous distribution of pharmacokinetic properties in the tumor and the requirement to detect small lesions. The diagnostic in breast MRI today is therefore based on simple curve shapes rather than pharmacokinetic modeling. In this work, some pharmacokinetic modeling of contrast arrival time (CAT) and variation of low temporal resolution are carried out to identify pitfalls in the application and to identify techniques beneficial for the diagnostic performance of breast MRI.

                  2478.     Preliminary Results Using a Split Dynamic Time Series for DCE MR-Mammography

Kjell-Inge Gjesdal1, Endre Grøvik2, Atle Bjørnerud3, Kathinka Kurz Dæhli4

1Sunnmøre MR-klinikk, Aalesund, Norway; 2University of Oslo, Oslo, Norway; 3Rikshospitalet University Hospital, Oslo, Norway; 4Stavanger University Hospital, Stavanger, Norway

This work presents the preliminary results of an ongoing MR-mammography study. In this study two dynamic sequences are run in an interleaved fashion during contrast enhancement. By using this approach both high temporal and high spatial resolution images can be produced and analyzed for the evaluation of breast cancer using one single dose of a Gd-based contrast agent.  A comprehensive list of biomarkers is presented along with their statistical values.

                  2479.     Can Diffusion Weighted Imaging/Apparent Diffusion Coefficient Mapping and Dynamic Contrast Magnetic Resonance Imaging Provide Histological Phenotyping of Breast Cancer in Basal and Luminal Subtypes?

Michael A. Jacobs1, Riham H. El Khouli2, Katarzyna J. Macura1, Sarah Mezban1, Ihab Kamel1, David A. Bluemke2

1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Department of Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States

By using a combined DWI/ADC and DCE approach to investigate histological characteristics of breast cancer a better understanding of breast cancer aggressiveness can be realized. Functional imaging such as DWI and DCE-MR is feasible and thus, combined DWI/ADC mapping, and DCE-MR provides radiological biomarkers of molecular environment and could provide targets for image-guided biopsy of highly aggressive tumor regions.

                  2480.     Principal Component Analysis of Breast DCE-MRI:  Evaluation of  Clinical Protocols  at Two Temporal Resolutions

Daria Badikhi1, Myra Shapiro-Feinberg2, Erez Eyal3, Edna Furman-Haran4, Dov Grobgeld1, Hadassa Degani1

1Biological Regulation, Weizmann Institute of Science, Rehovot, Israel; 2Radiology, Meir Medical Center, Kfar Sabah, Israel; 3Biological Regulation, Weizmann Institute of Science, Israel; 4Biological Services, Weizmann Institute of Science, Rehovot

Principal component analysis (PCA) of clinical breast DCE MRI datasets, recorded at two different temporal resolutions (80 s and 120 s), was tested and evaluated for its diagnostic ability. We found that PCA can differentiate with high accuracy between benign and malignant lesions at both temporal resolutions, however, discriminative ability between invasive ductal and lobular carcinoma can be reached only at the higher temporal resolution. Overall, PCA was found to be a useful, standardized, fast, and objective tool for computer aided diagnosis of breast lesions

                  2481.     Diffusion Weighted and Dynamic Contrast Enhanced MRI in Evaluation of Treatment Effects During Neoadjuvant Chemotherapy in Breast Cancer Patients

Line R. Jensen1, Benjamin Garzon1, Mariann G. Heldahl1, Tone F. Bathen1, Pål E. Goa1, Steinar Lundgren1,2, Ingrid S. Gribbestad1

1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Oncology, St. Olavs University Hospital, Trondheim, Norway

The purpose of this study was to use MRI for early evaluation of treatment effects in breast cancer patients undergoing neoadjuvant chemotherapy, and to identify MRI parameters at 3T that correlate to treatment response. In addition, the reproducibility of diffusion weighted MRI was assessed. The ADC values from two baseline examinations showed good reproducibility, with ICC of 0.84. The best predictors of pathologic treatment response were the change in the longest diameter measured on MRI, followed by mean and skewness of ADC, and Ktrans entropy.

                  2482.     Assessing 3D Resolution of DCE-MRI for Optimization and Standardization of Breast Screening Protocols

Marco Borri1, Maria Schmidt1, Erica Scurr1, Toni Wallace1, Steven Allen1, Nandita deSouza1, Martin O. Leach1

1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom

Spatial resolution of 3D fat-suppressed DCE pulse sequences depends on many parameters, and parity of protocols across breast screening centres is highly desirable. The objective of this work was to propose methods for quality assurance in breast screening programmes. We compared the image quality achieved with two different k-space sampling patterns, Radial and Linear, on a breast screening sequence. Resolution was evaluated with Test Objects and on Clinical Data, and, considering all three directions, was superior for Linear. The Image Analysis methodologies used were found to be robust and reproducible, and are therefore candidates to become quality assurance tools.

                  2483.     Influence of Spatial Heterogeneity on the Diagnostic Accuracy of DCE-MRI in Breast Tumor Characterization

Endre Grøvik1, Kjell-Inge Gjesdal2, Kathinka Kurz Dæhli3, Atle Bjørnerud4

1University of Oslo, Oslo, Norway; 2Sunnmøre MR-klinikk, Aalesund, Norway; 3Stavanger University Hospital, Stavanger, Norway; 4Rikshospitalet University Hospital, Oslo, Norway

This study investigates the influence of spatial heterogeneity on the diagnostic accuracy of DCE-MRI in breast tumor characterization. This is done by comparing the lesions VOI 50th-percentile versus VOI 95th-percentile values for a defined set of pharmacokinetic parameters, based on their ability for differentiating between malignant and benign lesions.  Our results suggest that a significant improvement in diagnostic accuracy can be obtained by identifying the 5% region indicating the highest malignancy in the defined tumor VOI.

                  2484.     Preliminary Results of a Physical Phantom for Quantitative Assessment of Breast MRI

Melanie Freed1,2, Jacco A. de Zwart3, Jennifer T. Loud4, Riham H. El Khouli5, Mark H. Greene4, Brandon D. Gallas1, Kyle J. Myers1, Jeff H. Duyn3, David A. Bluemke5, Aldo Badano1

1CDRH/OSEL/DIAM, FDA, Silver Spring, MD, United States; 2Department of Bioengineering, University of Maryland, College Park, MD, United States; 3NINDS/LFMI/Advanced MRI Section, National Institutes of Health, Bethesda, MD, United States; 4NCI/Clinical Genetics Branch, National Institutes of Health, Rockville, MD, United States; 5Department of Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States

We are developing a physical, tissue-mimicking phantom to be used for task-based, quantitative assessment of breast MRI protocols.  Here we present initial results of the phantom characterization and comparison to human data. Measured T1 and T2 relaxation values of the adipose- and glandular-mimicking phantom components agree with human values from the literature.  The structure of human and phantom images is compared using the covariance kernel and found to match within patient variation.

                  2485.     DSC MR-Mammography: Tumor Characterization Using Quantitative R2* Analysis

Endre Grøvik1, Kathinka Kurz Dæhli2, Atle Bjørnerud3, Kjell-Inge Gjesdal4

1University of Oslo, Oslo, Norway; 2Stavanger University Hospital, Stavanger, Norway; 3Rikshospitalet University Hospital, Oslo, Norway; 4Sunnmøre MR-klinikk, Aalesund, Norway

This work presents the transverse relaxation rate, R2*, as a quantitative biomarker for distinguishing between malignant and benign breast lesions. R2* was estimated on a pixel-by-pixel basis by assuming a mono-exponential dependence of a double-echo intensity scheme, yielding from a high temporal resolution sequence. The study suggested that the peak change in the transverse relaxation rate is a sensitive biomarker for tumor malignancy in DSC MR-mammography.

                  2486.     Simulation of Breast Tumor Growth from In-Situ to Invasive Cancer Using a Mathematical Model to Correlate with Lesion Phenotypes Shown on MRI

Ke Nie1, Jeon-Hor Chen1,2, Orhan Nalcioglu1, Min-Ying Lydia Su1

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

Mathematical modeling provides a unique means to simulate different cancer growth patterns. However, the current published models included only functional information, few of them considered the effect of environmental structure. In this study, we simulated the breast tumor growth in the duct by coupling tumor growth and duct wall deformation. By varying the key parameters, we could identify key mechanisms for DCIS to progress to invasive cancer. The simulation result is further correlated with the lesion phenotype shown on MRI. Understanding these biological growth patterns of DCIS may be further used to refine diagnostic criteria.

                  2487.     MRI Detection of Small Calcium Crystals in Air Bubble-Free Agarose Phantoms: Potential Applications to Imaging Microcalcifications in Breast Cancer

Bo Elizabeth Peng1, Sean Foxley2, Jeremy Palgen1, Robin Holmes2, Elizabeth Hipp2, Gillian Newstead2, Gregory S. Karczmar2, Devkumar Mustafi1,2

1Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States; 2Radiology, The University of Chicago, Chicago, IL, United States

We tested several MRI methods for the identification and characterization of small calcium crystals for probing microcalcifications in breast cancer. High-resolution MR images were acquired of small Ca-crystals imbedded in air bubble-free agarose phantoms in clinical and research magnets. Two types of Ca-crystals that are commonly associated with benign and malignant breast lesions, are clearly detectable and distinguishable by MRI, but not distinguishable on x-ray mammograms. The present results lend support to the feasibility of clinical visualization and analysis of microcalcifications by MRI. Detection of microcalcifications by MRI would increase sensitivity and specificity for breast cancer detection.

                  2488.     Microcalcification Detection Using Susceptibility Weighted Phase Imaging:  Cross-Correlation and Relative Magnetic Susceptibility Difference Methods

Richard Baheza1, Brian Welch2, John Gore3, Thomas Yankeelov3

1Biomedical Engineering, Vanderbilt, Nashville, TN, United States; 2Philips Healthcare; 3Institute of Imag Science and Dep of Radiology Sciences, Vanderbilt, Nashville, TN, United States

The possibility of detecting calcium deposits in breast has been investigated by simulation and experimentally. Susceptibility weighted imaging is used to simulate and measure signature due to magnetic susceptibility difference between calcium and water in tissue. Simulated and experimental data with different levels of signal to noise ratio (SNR) and resolution are analyzed by two methods. Crosscorrelation between simulated phase and data, and the relative magnetic susceptibility difference map, computed directly from data. Both methods are compared to locate 1mm object induced signature. Results suggest SNR≥20 and voxel size ≤ 0.25 mm (isotropic) are needed for both methods to work.

                  2489.     Detection of Breast Micro-Calcifications with MRI at 3T:

Riham Hossam El Din El Khouli1, David Thomasson1, Katarzyna Macura2, Sarah Mezban2, wei Liu3, Michael Jacobs2, Richard Edden4, Peter Barker2, David Bluemke1

1Radiology and Imaging Sciences, NIH/Clinical Center, Bethesda, MD, United States; 2Radiology and Radiological Sciences, Johns Hopkins University School of Medicine; 3NIH/NCI; 4Cardiff University

Micro-calcifications (< 1 mm) are a fundamental marker of breast cancer by x-ray mammography, especially for the early diagnosis of ductal carcinoma in situ (DCIS). However with MRI, micro-calcifications are rarely detected using standard pulse sequences. The purpose of this study was to optimize MRI approaches for detecting micro-calcifications in the breast in comparison to mammography and conventional MRI. We achieved high spatial resolution and good visualization of micro-calcifications using a proton density weighted ultra-short TE MRI sequence with radial reconstruction.  Ultra-short TE MRI has potential for detection of mammographically visualized micro-calcifications.

                  2490.     Distinguishing Molecular Subtypes of Breast Cancer Based on Computer-Aided Diagnosis of DCE-MRI

Shannon Agner1, Mark Rosen2, Sarah Englander2, Diana Sobers1, Kathleen Thomas2, John Tomaszewski3, Michael Feldman3, Shridar Ganesan1, Mitchell Schnall2, Anant Madabhushi1

1Biomedical Engineering, Rutgers University, Piscataway, NJ, United States; 2Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Pathology, University of Pennsylvania, Philadelphia, PA, United States

Previous studies based on visual inspection of breast tumors suggest that molecular subtypes of breast cancer are associated with distinct imaging phenotypes on DCE-MRI.  In this study, we develop a computer-aided diagnosis tool that utilizes textural kinetics, an attribute that captures time related changes in internal lesion texture, to distinguish between 20 triple negative (estrogen receptor (ER) negative/ progesterone receptor (PR) negative/ human epidermal growth factor (HER2) receptor negative) and 21 ER positive tumors.  Our CAD system was found to outperform classifiers that were driven by morphology, signal intensity kinetics, peak contrast texture, and pharmacokinetic parameters.

                  2491.     Improved 3D MR Imaging Using Virtual Coil Deconvolution for Effective Density Weighted Imaging (VIDED)

Marcel Gutberlet1, Anne Roth1, Dietbert Hahn1, Herbert Köstler1

1Institut fuer Roentgendiagnostik, University of Wuerzburg, Wuerzburg, Bavaria, Germany

A novel method is presented allowing improving 3D-MRI. Virtual coil deconvolution imaging for effective density weighted imaging (VIDED) combines the virtual coil concept with density weighted imaging. DW imaging allows improving the spatial response function at an optimal signal-to-noise ratio but at the expense of incoherent aliasing. In VIDED imaging this aliasing is suppressed by virtual coil deconvolution imaging which is a method allowing parallel imaging even for single receiver coils. VIDED imaging was applied in slice direction of 3D-MRI improving the slice profile, increasing the SNR up to 17% and the FOV in slice direction approximately by 25%.

                  2492.     Saturation-Recovery Snapshot FLASH Reduces RF Pulse Angle Inhomogeneity Artefacts in DCE-MRI of the Breast at 3T.

Che A. Azlan1,2, Trevor S. Ahearn1, Pierluigi Di Giovanni1, Scott I.K. Semple3, Fiona J. Gilbert1, Thomas W. Redpath1

1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, Scotland, United Kingdom; 2Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia; 3Department of Medical Physics, University of Edinburgh, Edinburgh, Scotland, United Kingdom

The objective of this study was to evaluate the effectiveness of Hoffmann's method of saturation-recovery snapshot FLASH (SRSF) to minimise the effect of  radiofrequency (RF) pulse angle inhomogeneity in breast dynamic contrast-enhanced (DCE)-MRI at 3T. We employed computer simulation and experiment on gel phantom for this purpose. The simulation shows that Hoffmann’s SRSF produces a robust saturation in the presence of expected RF inhomogeneity. The enhancement ratio data acquired broadly matches the simulation.  Implementing this method may be a solution to minimise the effects of RF pulse angle inhomogeneity in DCE-MRI of the breast at 3T.

                  2493.     Patient-Specific Calibration for Breast MRI: Breast-Coil Insertable Reference Phantom

Marieke Heisen1, Bo Peng2, Abbie Marie Wood3, Devkumar Mustafi2,3, Johannes Buurman4, Gillian M. Newstead3, Gregory S. Karczmar3

1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States; 3Radiology, The University of Chicago, Chicago, IL, United States; 4Healthcare Informatics, Philips Healthcare, Best, Netherlands

A unique calibration phantom was designed for routine use in breast MRI. It was used to correct the variable flip angles in a precontrast T1-measurement, and to inspect T1 sensitivity in the clinically employed T1-weighted dynamic contrast-enhanced protocol. The flip angle correction altered the T1 estimates in breast tissue significantly. The clinical protocol demonstrated an increase in signal intensity for decreasing T1 (as expected) until a certain level, after which signal attenuation occurred. The quality of the breast images acquired with the phantom in place was found to be normal by an experienced mammographer.

                  2494.     MR Imaging Features of Invasive Lobular Carcinoma: A Comparison with Invasive Ductal Carcinoma

Sung Hun Kim1, Jae Young Byun1, Eun Suk Cha1, Hyun Sook Kim1, Jae Jeong Choi1

1Radiology, College of Medicine, the Catholic University of Korea, Seocho gu, Seoul, Korea, Republic of

Invasive lobular carcinoma (ILC) is the second most common breast cancer after invasive ductal carcinoma (IDC). The incidence of ILC has continuously increased probably due to hormone replacement therapy. There were little studies to compare the imaging findings of ILC and IDC according to BI-RADS. The purposes of our study were to characterize the mammographic and MR imaing features of ILC and to compare these imaging features with those of IDC. Furthermore, the multiplicity and MRI diagnostic accuracy to detect the multiplicity apart from the index mass were determined.

                  2495.     BOLD Imaging of Compressed Breast Hemodynamics

Stefan Alexandru Carp1, Azma Mareyam1, Lawrence Wald1, David Alan Boas1

1Radiology, Massachusetts General Hospital, Charlestown, MA, United States

External compression induced hemodynamic changes in the breast have recently been investigated as potential biomarkers of breast cancer. Using fast diffuse NIR spectroscopy our group has demonstrated the non-invasive estimation of breast tissue blood flow and oxygen consumption. Consequently, we have designed an integrated MRI-optical breast compression platform for simultaneous acquisition of MR and optical images. MR scans provide structural prior information for optical reconstructions, as well as hemodynamic (BOLD) images for cross-validation against optically measured deoxy-hemoglobin. We describe the MRI breast compression platform and present initial results demonstrating contrast between the BOLD signal evolution in fibro-glandular vs. adipose tissue.

                  2496.     Development of Tissue Susceptibility Matched Pyrolytic Graphite Foam for Improved Frequency Selective Fat Suppression and Motion Suppression in Breast MRI

Gary Lee1, Patrick Goodwill1, Kevin Phuong2, Ben Inglis3, Brian Hargreaves4, Steven Conolly1,2

1Berkeley/UCSF Bioengineering Joint Graduate Group, Berkeley, CA, United States; 2Bioengineering, University of California - Berkeley, Berkeley, CA, United States; 3Henry J Wheeler, Jr. Brain Imaging Center, Berkeley, CA, United States; 4Radiology, Stanford University, Palo Alto, CA, United States

DCE breast MRI is emerging as the second most common diagnostic imaging modality for breast cancer, which has ~200,000 new cases and ~40,000 deaths annually.  However, breast MRI still lacks adequate specificity.  Magnetic susceptibility mismatches near the breast/air interface contribute to field inhomogeneities which make frequency selective fat suppression techniques more difficult.  We have developed tissue susceptibility matched pyrolytic graphite foam that is lightweight, safe for patients, and compatible with embedded RF coils.  PG foams may improve frequency selective fat suppression for breast MRI and provide more robust motion suppression, which may lead to improved specificity in breast cancer diagnosis.

                  2497.     Cactus Spines as Fiducials for MRI and Pathology Correlation of Ex-Vivo Human Lymph Nodes

Mies A. Korteweg1, Jaco J.M. Zwanenburg1, Cristian Koolstra, Paul J. van Diest2, Arjen J. Witkamp3, Willem P.Th.M. Mali1, Peter R. Luijten1, Wouter B. Veldhuis1

1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Pathology, University Medical Center Utrecht, Utrecht, Netherlands; 3Surgery, University Medical Center Utrecht, Netherlands

We describe the properties and suitability of cactus spines used as fiducial markers in ex-vivo human lymph nodes for the correlation of MRI to histopathology. In 42 nodes cactus spines were inserted before scanning at 7T. Afterwards the nodes were pathologically examined. Geometric distortions, susceptibility- or pathologic examination artifacts and identification on MRI were scored. Cactus spines were readily identified both on MRI and at histopathology. No interference was noted for either analysis. It was concluded that cactus spines are suitable fiducials which aid in the accurate correlation of intranodal imaging features to histopathology.

                  2498.     Local Excitation Important for Breast MR: Signal Energy from Outside the FOV Decreases Contrast Using Non-Cartesian Acquisitions

Matt Smith1, Krishna Kurpad2, Catherine Moran1, Xu Zhai1, Walter Block1,3, Sean Fain1,3

1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States

Regardless of the sampling technique, the volume of interest is degraded by excited signal energy outside the FOV. With 3D non-Cartesian acquisitions, the effect is incoherent streaking with noise-like appearance. Commercial receive only breast coils require slice/slab excitation from the body coil, exciting tissue outside the FOV. A local transmit/receive breast coil based on a solenoid design is compared with a commercial receive-only coil to demonstrate that local excitation minimizes the unwanted signal energy contaminating the FOV for non-Cartesian breast MR. Measurements of contrast are higher and more consistent using a 3DPR SSFP sequence with a local transmit/receive breast coil.

                  2499.     Adaptive 3D Radial MRI Based on Multidimensional Golden Means for Supine Breast Imaging

Peter Siegler1, Rachel W.-C. Chan2, Elizabeth A. Ramsay1, Donald B. Plewes1

1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

Dynamic contrast-enhanced breast MRI shows a high sensitivity for breast cancer but is commonly done in prone position which complicates its use for image-aided strategies. Recently, supine unilateral breast MRI with compensation for respiratory motion was successfully implemented. However, standard Cartesian sampling has no isotropic spatial resolution, which is desirable for image-aided applications. Here, 3D projection reconstruction based on multidimensional golden means was tested for use in supine breast MRI. The technique allowed post-processed compensation for respiratory motion, which is intrinsic in a supine position of the patient, without the need to choose any motion-compensation settings prior to the scan.

                  2500.     Towards a Microspectroscopy Catheter for Early-Stage Breast Cancer Detection

Debra Strick Rivera1, Jack W. Judy2, W Gilbert Clarke2, Dixie J. Mills3, Allen C. Chu2, Mark S. Cohen2

1Neurophysics, Max Planck Institute, Leipzig, Saxony, Germany; 2University of California, Los Angeles; 3Dr. Susan Love Research Foundation

Early-detection of breast cancer is unreliable, and of increased importance due to encouraging results of intraductal application of chemotherapy. We present a prototype radio-frequency transceiver for intraductal microspectroscopy, including soak-tests and heating studies. We demonstrate that the microcoil prototype is capable of resolving fat and water spectra in a sample with 5000-fold fewer spins than a state of the art matrix coil.

                  2501.     Breast Perfusion Imaging Using Arterial Spin Labeling

Misung Han1,2, Brian A. Hargreaves1, Bruce L. Daniel1, David C. Alsop3,4, Philip M. Robson, 4,5, Eric Han6, Pauline W. Worters1, Ajit Shankaranarayanan6

1Radiology, Stanford University, Stanford, CA, United States; 2Electrial Engineering, Stanford University, Stanford, CA, United States; 3Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 4Radiology, Harvard Medical School, Boston, MA, United States; 5Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA, United States; 6Applied Science Lab, GE Healthcare, Menlo Park, CA, United States

Malignant breast tumors induce high level angiogenesis, resulting in increased vascularity and perfusion. For breast MRI, dynamic contrast-enhanced MRI is most widely used to detect and characterize tumors; on the other hand, arterial spin labeling (ASL)  technique is very challenging due to low baseline flow in breasts. Here, we show our experience in 2D breast ASL using FAIR labeling and background suppression in both volunteers and patients. With our technique, higher perfusion signal was depicted in tumor.

                  2502.     Improved Fat Suppression with High Resolution Balanced Steady State Imaging in the Breast

Dorothee Barbara Engel1, Catherine Judith Moran2, Fred Kelcz3, Stephan O. Schoenberg1, Walter Block2

1Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany; 2Department of Medical Physics, University of Wisconsin, Madison, WI, United States; 3Department of Radiology, University of Wisconsin, Madison, WI, United States

While the Dynamic Contrast Enhanced (DCE) acquisition remains the centerpiece of breast MRI, both signal intensity and the depiction of lesion morphology in T2-weighted images can help to distinguish malignant versus benign lesions. With TRs on the order of seconds, T2-weighted acquisitions are generally inefficient and most often acquired with high in-plane resolution but low through plane resolution. A radial bSSFP acquisition termed 3DPR-SSFP has been shown to provide improved depiction of lesion morphology in comparison to conventional T2-weighed acquisitions. We evaluate the performance of two methods for improving fat suppression of 3DPR-SSFP while retaining the advantage of clear depiction of fine morphological details in the breast.

                  2503.     Resolving Arterial Phase in Dynamic Breast MRI Using a Fast TWIST Acquisition During Injection Delay

Karl-Heinz Herrmann1, Pascal A. Baltzer, Ines Krumbein, Christian Geppert2, Werner A. Kaiser, Jürgen R. Reichenbach1

1Medical Physics Group,  Department of Diagnostic and Interventional  Radiology, University Hospital Jena, Jena, Thüringen, Germany; 2MR Oncology, Siemens Healthcare, Erlangen

In MR Mammography pathologic vascularisation is utilized for the diagnosis of tumors. Many standard dynamic MRM protocols contain a delay of 35s, during which the contrast agent is applied, between the native scan and the following multiple post-CA scans. This injection delay can be efficiently used to acquire additional dynamic data sets with both high temporal (5.7s) and spatial resolution (0.9x0.9x1.5mm) using a 3D gradient echo view sharing sequence with stochastic trajectories (TWIST). This allows to resolve the arterial phase of the contrast agents first pass and helps to detect anomalous arterial supply vessels to suspect lesions.

Lung & Mediastinum MRI

Hall B                        Wednesday 13:30-15:30                                                                                                        

                  2504.     Inflammation Assessment in the Lungs of LPS-Challenged Rodents: Comparison Between Radial Ultra-Short Echo Time (UTE) and Cartesian MR Imaging

Magdalena Zurek1, Laura Carrero-Gonzalez2,3, Selina Bucher2, Thomas Kaulisch2, Detlef Stiller2, Yannick Crémillieux1

1Université de Lyon, Laboratoire CREATIS-LRMN, Lyon, France; 2Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany; 3Universidad Complutense de Madrid, Madrid, Spain

A radial ultra short-echo time (UTE) sequence has been shown to be appropriate in pulmonary imaging due to its robustness against motion and its improved image resolution. In this study, we evaluated the accuracy of edema detection using two protocols based on conventional-Cartesian and UTE radial imaging approaches. Despite degraded image quality in case of Cartesian images due to the motion, similar inflammation extent was found for both approaches. The UTE technique, applied under free-breathing conditions, will certainly prove to be quite useful in routine MR investigations applied on models of lung diseases associated with inflammation or mucous hypersecretion.

                  2505.     Ultrashort Echo Time (UTE) MR Lung Imaging with Respiratory Motion Compensation

Jiangsheng Yu1, Yiqun Xue1, Hamidreza Saligheh Rad1, Hee Kwon Song1

1Laboratory for Structural NMR Imaging, Department of Radiology,, University of Pennsylvania, Philadelphia, PA, United States

Ultra-short echo time (UTE) MRI has been successfully applied to lung imaging, but so far the issue of respiratory motion during imaging the lung parenchyma has not yet been addressed. In this work, a respiratory motion-compensated UTE lung MRI technique is presented. This technique applies the golden-angle view increment strategy in conjunction with respiratory self-gating to reconstruct images at different respiratory phases to reduce respiratory motion artifacts. The in-vivo results demonstrate that lung image quality is significantly enhanced with improved visualization and delineation of lung vasculature, as well as improved SNR, as compared to conventional gradient echo images.

                  2506.     Comparison of Lung T2* Measurements at 1.5T and 3.0T with Ultrashort Echo Time (UTE) Sequence

Jiangsheng Yu1, Yiqun Xue1, Hee Kwon Song1

1University of Pennsylvania, Philadelphia, PA, United States

Accurate assessments of lung T2* may be important as it has the potential to detect structural and functional changes caused by lung diseases such as emphysema, chronic bronchitis and fibrosis. While measurements have been carried out in both animals and humans at 1.5T, studies on human lung at 3T have not yet been reported. In this work, we compare T2* values in normal human lungs at 1.5T and 3.0T using an ultrashort echo time (UTE) pulse sequence. Results show the average lung T2* of 0.72 (±0.17) ms at 3.0T is considerably shorter than 2.2 (±0.43) ms at 1.5T.

                  2507.     Time-Resolved Lung Perfusion- And Ventilation-Weighted MRI by Wavelet Analysis

Grzegorz Bauman1,2, Julien Dinkel3, Michael Puderbach3, Lothar Rudi Schad2

1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Computer Assisted Clinical Medicine, University of Heidelberg, Mannheim, Germany; 3Department of Radiology, German Cancer Research Center, Heidelberg, Germany

Non-contrast based assessment of the pulmonary function using MRI remains challenging. We propose a novel post-processing method based on the Wavelet analysis to retrieve information about pulmonary perfusion and ventilation. The method utilizes rapid acquisition of time-resolved MR-data using a 2D Steady-State Free Precession sequence implemented on a 1.5 T whole-body MR-scanner. Wavelet transform allows for a robust analysis of non-stationary physiological signals (respiratory/cardiac cycles). The aim of this study was to show feasibility of the proposed approach.

                  2508.     Improved Visualization of Pulmonary Parenchyma Using SSFP Sequence for Dynamic MR-Studies

Grzegorz Bauman1,2, Michael Deimling3, Michael Puderbach4, Lothar Rudi Schad2

1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Computer Assisted Clinical Medicine, University of Heidelberg, Mannheim, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Department of Radiology, German Cancer Research Center, Heidelberg, Germany

In lung MRI, due to the fast signal dephasing, respiratory motion and cardiac pulsation, very fast imaging sequences using short repetition times or the application of triggering techniques are required. The aim of this work was to numerically simulate and optimize the Steady-State Free Precession (SSFP) imaging scheme for dynamic studies on a 1.5 T whole-body MR-scanner. Fast imaging with the SSFP sequence using a combination of the central k-space sampling, parallel imaging, high bandwidth and minimal inter-echo sampling allowed to improve the visualization of the pulmonary tissue sufficiently for functional lung MRI.

                  2509.     High Resolution T2 Weighted Lung Imaging with a Radial Turbo Spin-Echo Sequence

Michael Völker1, Philipp Ehses1, Martin Blaimer2, Felix Breuer2, Peter Michael Jakob1,2

1Department of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2Research Center for Magnetic Resonance Bavaria (MRB), Würzburg, Germany

A segmented radial Turbo Spin-Echo (rTSE) sequence was investigated towards its feasibility for high resolution lung imaging under free breathing conditions. No triggering techniques were involved to define the limits of the sequence itself. Unlike ultrafast singleshot techniques such as HASTE resolution is not intrinsically limited by the T2 signal decay while motion, especially of the beating heart, poses only a small problem in comparison with conventional Cartesian TSE. In addition, arbitrary T2 contrasts may be generated by postprocessing a single dataset allowing for the calculation of quantitative T2 maps.

                  2510.     Proton MRI of Human Lung Using 2D Radial Acquisition at 1.5 T and 3.0 T

Jascha Zapp1, Simon Konstandin1, Lothar R. Schad1

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

MRI of the lung is challenging because of low proton density, respiratory and cardiac motion and susceptibility effects at air-tissue interfaces. A healthy volunteer was examined using a 2D radial gradient echo technique (resolution: 0.8mm x 0.8mm x 5.0mm) with conventional (full) RF pulses (TE=0.77ms) and half RF pulses (TE=0.02ms) at 1.5T and 3.0T. Average SNR in lung parenchyma resulted in an increase of 56% at 3.0T compared to 1.5T with TE=0.02ms. The result shows that SNR in proton MRI of human lung at 3.0T is superior to 1.5T when using a 2D radial sequence with ultrashort echo time.

                  2511.     Feasibility of Using Linear Combination SSFP for Lung MRI at 3 T

Atiyah Yahya1,2, Keith Wachowicz1,2, B. Gino Fallone1,2

1Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada; 2Department of Oncology, University of Alberta, Edmonton, Alberta, Canada

MRI of the lungs is challenging because of the low proton density and because of the large number of air-tissue interfaces which create susceptibility gradients.  Lung MRI has shown to be feasible at 3 T using the HASTE sequence with parallel imaging.  In this work we examine the feasibility of applying Linear Combination SSFP (LCSSFP) for lung MRI at 3 T.  Experiments were conducted on a normal volunteer and lung images were acquired with both HASTE and LCSSFP.  The images acquired with LCSSFP were clearer and did not suffer from blurring compared to the HASTE images.

                  2512.     MRI as a Non-X Ray Based Imaging Alternative to Study Experimental Lung Fibrosis Induced by Bleomycin in Rats

Anna Louise Babin1,2, Catherine Cannet1, Christelle Gerard1, Clive P. Page3, Nicolau Beckmann1

1Global Imaging Group, Novartis Institutes for BioMedical Research, Basel, BS, Switzerland; 2Sackler Institute of Pulmonary Pharmacology, King’s College, London, SE1 1UL, United Kingdom; 3Sackler Institute of Pulmonary Pharmacology, King's College, London, SE1 1UL, United Kingdom

Micro-CT has been shown to be useful in characterizing anatomical changes related to lung fibrosis models in rats. However, radiation doses are an issue both in the clinics and in experimental studies, and repetitive measurements are limited. In the present work, we show that proton MRI can be used to follow longitudinally in spontaneously breathing rats the development of structural changes related to lung fibrosis induced by bleomycin administration, and thus MRI represents a non-X ray based imaging alternative to study experimental fibrosis.

                  2513.     Non-Invasive Assessment of Mucociliary Clearance with Micron-Sized Iron Oxide Particles in Rat Lungs

Selina Bucher1, Michael Neumaier1, Sascha Koehler2, Birgit Jung3, Detlef Stiller1

1In-Vivo Imaging Unit, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Method Development, Bruker BioSpin MRI GmbH, Ettlingen, Germany; 3Dept. of Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and mucus production. Because an excess of mucus triggers infections, an efficient mucociliary clearance (MCC) is important. To detect therapy-induced changes in MCC, non-invasive imaging techniques are needed. We used 2D radial MRI and micron-sized iron-oxide particles to evaluate MCC in the rat lung, where four different iron-oxide particles yielded an attenuated MR signal. Clearance of 4.5 µm-sized particles occurred within one day, whereas smaller and larger particles were not cleared. Our results indicate a great potential for MRI with micron-sized iron-oxide particles to visualize and quantify MCC in patients.

                  2514.     Fast and Robust T1 Mapping of the Human Lung at Different Sites

Jakob Kreutner1, Ruobing Yang2, Simon Triphan1,3, Martin Blaimer3, Felix Breuer3, Peter Michael Jakob1,3

1Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2University of British Columbia, Vancouver, Canada; 3Research Center Magnetic Resonance Bavaria, Würzburg, Germany

Characterization of pathologic lung tissue necessitates a robust method for diagnosis. T1 relaxation times provide information about oxygen transfer in the lung. To demonstrate the robustness of the IR Snapshot FLASH sequence we repeatedly quantified T1 at different sites using a lung phantom made of several Gd-DTPA doped bottles. The results show an excellent reproducibility of the relaxation times.

                  2515.     Mapping the Ventilation–perfusion Ratio in Chronic Obstructive Pulmonary Disease Using Oxygen-Enhanced MRI

Penny Louise Hubbard1,2, Geoff J. M. Parker1,2, Dave Singh3, Jørgen Vestbo3, Simon S. Young4, Eva Bondesson5, Lars E. Olsson6, Josephine H. Naish1,2

1Imaging Sciences and Biomedical Engineering, University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, United Kingdom; 3Airway Pharmacology Group, School of Translational Medicine,, University Hospital of South Manchester Foundation Trust, Manchester, United Kingdom; 4AstraZeneca R & D, Charnwood, United Kingdom; 5AstraZeneca R & D, Lund, Sweden; 6AstraZeneca R & D, Mölndal, Sweden

We present a regional characterisation of the ventilation-perfusion ratio using a novel two-compartment physiological model analysis of oxygen-enhanced MRI data. A preliminary analysis of subjects with chronic obstructive pulmonary disease and age-matched healthy subjects shows how changes in T1 can be related directly to physiological parameters indicative of lung function. This novel MR method is minimally-invasive and repeatable, and reveals enhanced sensitivity to the early onset of disease than more traditional global lung function measures.

                  2516.     Physiological Modelling of Oxygen-Enhanced MRI in the Lung

Josephine Helen Naish1,2, Geoff J M Parker1,2

1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 2Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom

We present a two-compartment model of pulmonary oxygen-enhanced MRI (OE-MRI) based on known gas exchange processes in the lung. The model relates the rate of change of oxygen partial pressure to physiological parameters describing ventilation, perfusion and blood oxygen solubility and allows quantitative V/Q maps to be extracted from OE-MRI data.

                  2517.     Fast, High Resolution T1-Mapping of the Human Lung Using an Inversion Recovery Radial Golden Angle Acquisition.

Simon Triphan1, Philipp Ehses2, Martin Blaimer1, Jakob Kreutner2, Felix Breuer1, Peter Jakob, 12

1Research Center Magnetic Resonance Bavaria e.V., Würzburg, Bayern, Germany; 2Experimentelle Physik 5, Universität Würzburg, Würzburg, Bayern, Germany

The quantification of T1 in the human lung at 1.5T using an Inversion Recovery Snapshot FLASH experiment was improved by employing an asymmetric radial readout scheme: By measuring k-space with golden angle radial projections with maximal echo asymmetry, echo times could be significantly reduced yielding improved signal from lung tissue. The acquisition scheme was combined with a KWIC-filter technique to reconstruct images at subsequent points in time along signal recovery, thereby achieving a higher temporal resolution compared to a cartesian measurement. The improved SNR and higher temporal resolution was used to calculate T1 maps at an increased spatial resolution.

                  2518.     Feasibility Study of in Situ Lung MRE in a Porcine Model: Correlation of Shear Stiffness and Transpulmonary Pressures

Yogesh K. Mariappan1, Arunark Kolipaka1, Richard L. Ehman1, Kiaran P. McGee1

1Department of Radiology, Mayo Clinic, Rochester, MN, United States

Previous lung magnetic resonance elastography (MRE) animal experiments have indicated that it is feasible to quantitate the shear modulus of lungs with 1H MRI with the driver in direct contact with the lungs. Here, we tested the applicability of this technique in an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. Further, the feasibility of this technique to measure the change in stiffness of the lung parenchyma as a function of transpulmonary pressure was also evaluated. It was found that lung stiffness can be quantified with this setup and that shear stiffness increases with increasing transpulmonary pressure.

                  2519.     MRE of in Vivo Human Lung Parenchyma: Feasibility Study of Motion Encoding Using the Imaging Gradients with 1H MRI

Yogesh K. Mariappan1, Kevin J. Glaser1, Armando Manduca1, Richard L. Ehman1, Kiaran P. McGee1

1Department of Radiology, Mayo Clinic, Rochester, MN, United States

Application of Magnetic Resonance Elastography within the lung is challenging because of the inherently low 1H MR signal. The additional motion-sensitizing gradients inserted into the conventional MR sequence necessary for MRE results in longer echo times, further degrading the signal from lung parenchyma. We hypothesized that with appropriate manipulations, the crusher gradients of a spin echo sequence can be used for motion detection, while maintaining a short echo time. We tested this hypothesis in healthy human volunteers and found that it is feasible to detect motion within the lungs with the imaging gradients while maintaining sufficient lung tissue signal.

                  2520.     A Novel Method Using Proton MRI and Image Registration to Investigate Relative Regional Pulmonary Compliance

Alexandra Rose Morgan1,2, Geoff J.M. Parker1,2, Marietta L.J. Scott3, Tim F. Cootes1,2, Josephine H. Naish1,2

1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, United Kingdom; 2The Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom; 3AstraZeneca, Alderley Park, Macclesfield, United Kingdom

Current diagnosis methods in chronic obstructive pulmonary disease (COPD) are not capable of examining regional pathological changes in mechanical properties. We have developed a method for investigating relative regional pulmonary compliance using proton magnetic resonance imaging (MRI). A 2D half-Fourier acquired single-shot turbo spin-echo (HASTE) sequence was optimised for lung imaging. A mesh-based group-wise affine image registration was applied to images ordered according to respiratory cycle position. Information from the registration allowed relative regional compliance measures to be extracted and mapped over the lung. Maps show differences between healthy volunteers and COPD patients and can indicate likely regions of disease.

                  2521.     Quantification of Bleomycin Induced Lung Injury by Means of 1H Magnetic Resonance Elastography

Kiaran P. McGee1, Richard L. Ehman1, Rolf D. Hubmayr2, David L. Levin1, Mary Breen3, Debora Rasmussen2, Yogesh K. Mariappan1

1Radiology, Mayo Clinic and Foundation, Rochester, MN, United States; 2Pulmonology & Critical Care, Mayo Clinic and Foundation, Rochester, MN, United States; 3College of Arts and Sciences, Boston College, Boston, MA, United States

Interstitial lung disease (ILD) induced end stage fibrosis is a multi phase process that includes presence of an exudate followed by either edema clearance or organization of the space filling material and fibrosis. We have applied magnetic resonance elastography (MRE) to determine if this method can differentiate between normal and those processes associated with ILD. MRE estimates of shear modulus increased following lung injury when compared to an air-filled lung suggesting that lung injury-induced restructuring of lung parenchyma results in changes to the intrinsic mechanical properties of the lung and that these changes can be quantitated with MRE.

                  2522.     Free-Breath DCE MRI for Solitary Pulmonary Nodule with Motion Correction Based on Non-Rigid Image Registration

Junichi Tokuda1, Hatsuho Mamata1, Ritu R. Gill1, Samuel Patz1, Nobuhiko Hata1, Robert E. Lenkinski2, David J. Sugarbaker3, Hiroto Hatabu1

1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Department of Surgery, Brigham and Women's Hospital, Boston, MA, United States

We demonstrate perfusion analysis of solitary pulmonary nodule based on free-breath DCE MRI. In DCE MRI studies, the kinetics of signal variation at lesions following the administration of the contrast agent is analyzed from time-intensity curve. Thus, it is crucial to measure the signal intensity at the corresponding regions in each frame in the time-series of images for accurate signal intensity curve analysis. However, the respiratory motion of the subjects during scans causes misalignment of anatomical regions among the frames resulting inaccuracy of time-intensity curve. In this paper, we compare perfusion analyses based on motion-compensated MRI data and manual measurement.

                  2523.     Non-Contrast-Enhanced Pulmonary MR Imaging: Comparison of Capability for Nodule Screening Between 1.5T and 3.0T MR Systems

Keiko Matsumoto1, Yoshiharu Ohno1, Hisanobu Koyama1, Munenobu Nogami1, Daisuke Takenaka1, Yumiko Onishi1, Nobulazu Aoyama2, Hideaki Kawamitsu2, Tsutomu Araki3, Kazuro Sugimura1

1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan; 3Department of Radiology, University of Yamanashi, Japan

Academic and social interest to radiation induced cancer development on CT examination is increasing in the world.  Since 1997, several investigators have suggested that pulmonary MR imaging on 1.5T MR system has potential for nodule detection as substitution to CT.  To the best of our knowledge, no one directly compare the capability of non-contrast-enhanced (non-CE) pulmonary MRI for pulmonary nodule detection between 1.5T and 3.0T MR systems.  The purpose of this study was to prospectively and directly compare the capability of non-CE pulmonary MR imaging on 3.0T MR system for nodule detection than that on 1.5T MR system.

                  2524.     Blood Supply and Vascularization of Lung Cancer, Studies by MRI and Optical Imaging

Gregory Jacques Ramniceanu1, Erez Eyal2, Inbal Biton3, Nava Nevo2, Raanan Margalit4, Raya Eilam-Altstadter3, Hadassa Degani1

1Biological regulation, Weizmann Institute of Science, Rehovot, Israel; 2biological regulation, Weizmann Institute of Science, Rehovot, Israel; 3Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel; 4Immunology, Weizmann Institute of Science, Rehovot, Israel

The lung vasculature is composed of two systems, the bronchial and the pulmonary circulations. It is still unknown which of these two circulations, or both, contribute to the feeding of lung tumors during their progression .To answer this basic we characterize the perfusion parameters and the role of angiogenesis and interstitial fluid pressure in the lung tumors using MRI and optical imaging methods. Specifically we focus on imaging interstitial fluid pressure using a slow infusion protocol of the contrast agent.

                  2525.     DC Gated High Resolution 3D MRI of the Human Lung Under Free Breathing

Stefan Weick1, Philipp Ehses2, Martin Blaimer2, F. A. Breuer2, P. M. Jakob1,2

1Department of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; 2Research Center for Magnetic Resonance Bavaria (MRB)

In this work, 3D Flash examinations of the human lung were performed during free respiration using the DC signal for self-gating. Short echo times (TE) are required to provide sufficiently SNR because of the short T2* of the lung tissue. It is shown that the DC signal can be acquired after the actual imaging module still providing enough quality for respiratory gating and simultaneously providing very short echo times. The maxima and minima of the DC signal were used to define threshold values for data rejection and high resolution images were reconstructed retrospectively.

                  2526.     Dynamic MR Perfusion Imaging Vs. Time-Resolved MR Angiography Vs. MDCT: Disease Extent Assessment and Outcome Prediction for Patients with Acute Pulmonary Thromboembolism

Keiko Matsumoto1, Yoshiharu Ohno1, Hisanobu Koyama1, Yumiko Onishi1, Daisuke Takenaka1, Munenobu Nogami1, Nobukazu Aoyama2, Hideaki Kawamitsu2, Tsutomu Araki3, Kazuro Sugimura1

1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Division of Radiology, Kobe University Hospital, Kobe, Japan; 3Department of Radiology, University of Yamanashi, Japan

MDCT has become the first imaging examination in suspected APTE patients.  As well as technical advances of CT, technical advances of magnetic resonance (MR) imaging make it possible to obtain time-resolved MR angiography or perfusion MR imaging (perfusion MRI) in APTE patients.  We hypothesized that quantitatively assessed pulmonary perfusion parameters from contrast-enhanced perfusion MRI have potential for disease extent assessment and have predictive capability of patient outcome in APTE patients.  The aim of our study was therefore to directly compare the capability for disease severity assessment and patient outcome prediction of MDCT and MR techniques in APTE patients.

                  2527.     Exploration of Gas Flow During High Frequency Oscillated Ventilation by  19F-Gas-MRI

Janet Friedrich1, Julien Rivoire1, Alexander Wiegbert Scholz2, Maxim Terekhov1, Rainer Köbrich2, Lars Krenkel3, Claus Wagner3, Laura Maria Schreiber1

1Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany; 2Department of Anesthesiology, Johannes Gutenberg University Medical Center, Mainz, Germany; 3German Aerospace Center, Göttingen, Germany

To detect convective gas flow inside the large airways during high frequency oscillated ventilation (HFOV) the fluorinated contrast gas Heptafluoropropane was used for 19F-MRI. In a first study the comparison between constant flow measurements and Computational Fluid Dynamics (CFD) simulations provided a good agreement. In a following experiment oscillated flow was applied to a lung phantom consisting of ventilation bag and long pipe. The pressure wave inside the pipe was explored point-by-point and corresponding velocities were determined. With these experiments it could be shown for the first time that flow measurement during HFOV using fluorinated contrast gas is feasible.

Hyperpolarized Gas Imaging

Hall B                        Thursday 13:30-15:30                                                                                                           

                  2528.     Comparison of Hyperpolarized 3He and 129Xe for Measurement of Absolute Ventilated Lung Volume of Rat Lungs

Matthew S. Fox1,2, Alexei Ouriadov1, William Dominguez-Viqueira1,3, Marcus Couch1,2, Giles E. Santyr1,3

1Imaging, Robarts Research Institute, London, Ontario, Canada; 2Physics and Astronomy Dept, University of Western Ontario, London, Ontario, Canada; 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada

Magnetic Resonance (MR) imaging using hyperpolarized noble gases (HNG) 3He and 129Xe provides a non-invasive approach for probing both lung function and structure.  Measurement of ventilated lung volumes are useful for characterizing chronic obstructive pulmonary disease, quantifying the diffusing capacity of xenon and may be useful in measuring lung mechanics such as compliance.  The objective of this work was to perform 3D MR imaging in rats under similar ventilation conditions and compare measured ventilated volumes obtained from the two gases in an effort to show that 129Xe is just as accurate as 3He which has already been validated by microCT.

                  2529.     Hyperpolarized Xenon-129 Ventilation MRI: Preliminary Results in Normal Subjects and Patients with Lung Disease

Talissa A. Altes1, John P. Mugler1, Isabel M. Dregely2, Stephen Ketel3, Iulian C. Ruset2,3, Eduard E. de Lange1, F William Hersman2,3, Kai Ruppert1

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH; 3Xemed, LCC, Durham, NH

The purpose of this study was to assess the feasibility and currently achievable quality of hyperpolarized xenon-129 ventilation (spin density) MRI in normal subjects (n=7) and patients with asthma (n=5), chronic obstructive pulmonary disease (COPD) (n=4), cystic fibrosis (CF) (n=1), and sickle cell disease (SCD) (n=1). As seen previously with helium, the normal subjects had homogeneous ventilation with few if any ventilation defects.  Focal ventilation defects were found in all patients with obstructive lung diseases.  Qualitatively the hyperpolarized xenon-129 ventilation images are similar although not identical to previously acquired hyperpolarized helium-3 ventilation images in different patients with similar disease states.

                  2530.     Synchronised Acquisition of Hyperpolarised 3He and 1H MR Images of the Lungs During the Same Breath-Hold

Jim M. Wild1, Salma Ajraoui1, Martin H. Deppe1, Steven R. Parnell1, Helen Marshall1, James Swinscoe2, Matthew Hatton2, Juan Parra-Robles1, Rob H. Ireland1

1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom; 2Weston Park Hopital, Sheffield, United Kingdom

Combined 1H MRI of lung anatomy with hyperpolarised gas MRI of lung function has previously required acquisition of separate breath-hold exams, with separate MRI pulse sequences and dedicated RF coils, resulting in images that were not spatially registered or temporally synchronised. Here 1H anatomical and 3He ventilation MRI from human lungs were acquired in the same breath-hold using decoupled RF hardware and optimised dual acquisition MRI pulse sequences. The resulting 3He and 1H images acquired in the same breath (from volunteers and patients with lung disease), showed superior registration to those acquired in repeat breath-hold manoeuvres.

                  2531.     Inter-Observer Reproducibility of Longitudinal Hyperpolarized Helium-3 Magnetic Resonance Imaging of Chronic Obstructive Pulmonary Disease

Miranda Kirby1,2, Lindsay Mathew1,2, Andrew Wheatley1, David G. McCormack3, Grace Parraga1,4

1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario; 3Division of Respirology, Department of Medicine, The University of Western Ontario; 4Graduate Program in Biomedical Engineering, The University of Western Ontario

Here we evaluate the associations between hyperpolarized Helium-3 Magnetic Resonance Imaging (3He MRI) longitudinal changes measured in Chronic Obstructive Pulmonary Disease (COPD) ex-smokers, with SNR and inter-observer variability. Spin density images for 15 subjects were segmented to obtain ventilation defect volume (VDV) measurements at baseline and 26 months. Inter-observer reproducibility was determined for two observers; ICC= .93, COV= 26% and r2= .78 (p<.0001).  There was no significant relationship between image SNR and inter-observer variability (r=-.06, p=.75). Therefore, measurement variability is not affected by SNR and increases in VDV at follow-up may reflect COPD airway functional changes, suggestive of disease progression.

                  2532.     Assessing the Persistence of Ventilation Defects in Asthmatics at Baseline and Following Methacholine Challenge Using Hyperpolarized 3He MRI

Yanping Sun1, Linxi Shi1,2, Guoen Jin1, Sanaz Zhalehdoust Sani3, Justin L. Lui3, Stephen J. Krinzman4, John Mark Madison4, Kenneth R. Lutchen3, Mitchell S. Albert1

1Radiology, University of Massachusetts, Worcester, MA, United States; 2Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States; 3Biomedical Engineering, Boston University, Boston, MA, United States; 4Pulmonary, University of Massachusetts, Worcester, MA, United States

We used hyperpolarized 3He MR to image subjects with asthma at two scanning sessions 45 days apart; during each session, baseline and post-methacholine scans were collected. We found that post-methacholine, defect number increased by an average of 172%. The percentage of defects that remained in the same location between imaging sessions was 75% ± 40 between baseline scans, but 96% ± 4 between post-methacholine scans. Thus, methacholine provocations in asthmatics increased defect number, but defects tended to remain in the same location from one provocation to another. Our results suggest that asthma dysfunction has an important localized component.

                  2533.     Using Hyperpolarized 3He MRI to Evaluate Therapeutics in Cystic Fibrosis Patients

Yanping Sun1, Brian O'Sullivan2, Ronn P. Walvick1,3, Austin L. Reno1, Linxi Shi1,4, Dawn Baker2, Joey Mansour1, Mitchell S. Albert1

1Radiology, University of Massachusetts, Worcester, MA, United States; 2Pediatrics, University of Massachusetts, Worcester, MA, United States; 3Biomedical Engineering, Worcester Polytechnic Institute  , Worcester, MA, United States; 4Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States

Cystic fibrosis (CF) is a genetic disease impairing chloride permeability in epithelial cells; CF causes thick, viscous mucus, leading to lung congestion, frequent infections, and over time, debilitating lung damage. In this study, we used HP 3He static ventilation MRI scans to assess improvement of lung ventilation in three CF patients following treatment with intravenous antibiotics, daily administration of hypertonic saline, and administration of rhDNase. In one of the subjects, there was a 25% increase in ventilation measured by HP 3He MRI following treatment, which corresponded with spirometry. The other two subjects showed no changes in 3He ventilation.

                  2534.     Detection and Characterization of Physiologic Lung Changes After Placement of Bronchial Valves: A Case Study.

Jaime Mata1, Talissa Altes1, Steve Springmeyer2, Jonathon Truwit1, Eduard de Lange1, Peter Sylvester1, John Mugler III1

1University of Virginia, Charlottesville, VA, United States; 2Spiration Inc, Redmond, WA, United States

The purpose was to determine whether hyperpolarized helium-3 (HHe) ventilation and diffusion MR imaging can detect changes in lung function and microstructure resulting from bronchial valve placement.

One subject was imaged with HHe, pre and 6-month post IBV placement. Physiological changes of the lung were observed and quantified. 

In conclusion, HHe MR imaging appears to provide a safe, non-invasive method for measuring functional and structural changes in the lungs after IBV placement.

                  2535.     Acinar Structural Changes in Mild COPD Detected by in Vivo Lung Morphometry with Hyperpolarized Helium-3 MRI

James D. Quirk1, Barbara A. Lutey2, Jason C. Woods1,3, Alexander L. Sukstanskii1, Mark S. Conradi, 1,3, Mario Castro2, David S. Gierada1, Dmitriy A. Yablonskiy1,3

1Radiology, Washington University School of Medicine, St. Louis, MO, United States; 2Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States; 3Physics, Washington University, St. Louis, MO, United States

In vivo lung morphometry with hyperpolarized helium-3 MRI is a sensitive method for detecting early emphysema and provides a unique insight into changes in the acinar microstructure.  We utilized this technique to measure acinar geometrical parameters in 30 smokers and 5 healthy volunteers.  Our results support the view that early emphysema progresses through dilation of alveolar ducts with retraction of alveolar walls.  We also detected significant disease heterogeneity across the lung and suggest that these patterns can provide important insights into disease phenotypes and are valuable for monitoring disease progression and regression.

                  2536.     Golden Angle Radial Imaging for Improved Visualisation of Initial Stages of Inhalation in Dynamic 3He Lung MRI

Helen Marshall1, Salma Ajraoui1, James M. Wild1

1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

The study of ventilation dynamics with hyperpolarised 3He requires a fast imaging sequence to capture the flow of contrast into the lungs.  Radial acquisition, among other sequences, has previously been demonstrated for this purpose.  However, images from a standard radial acquisition are constrained to a fixed resolution determined at the acquisition stage.  Here golden angle radial sampling was used to image the inhalation of hyperpolarised 3He and compared to a standard, sequential radial acquisition.  Golden angle radial imaging enabled reconstruction of the dynamic dataset at any chosen spatio-temporal resolution, providing improved visualisation of the initial stages of inhalation.

                  2537.     On the Relationship Between 3He ADC and Lung Morphometrical Parameters

Alexander L. Sukstanskii1, James D. Quirk1, Jason C. Woods1,2, David S. Gierada1, Barbara A. Lutey3, Mark S. Conradi2, Dmitriy A. Yablonskiy1,2

1Radiology, Washington University, St. Louis, Misssouri, United States; 2Physics, Washington University, St. Louis, MO, United States; 3Internal Medicine, Washington University, St. Louis, MO, United States

The apparent diffusion coefficient (ADC) of hyperpolarized 3He gas in lungs increases in emphysema and can serve as a biomarker of the disease progression. It is not clear, however, how ADC relates to lung microstructure. In the present communication, using 3He-based in vivo lung morphometry technique, we demonstrate that ADC and a standard histological parameter – mean chord length (Lm) reflect lung microstructure parameters in different ways. As a result, a there is no unique relationship between ADC and Lm. At the same time, 3He-based lung morphometry allows quantification of the lung microstructure in terms of Lm, surface-to-volume ratio and other standard histological parameters.

                  2538.     Modelling Non-Gaussian 3He Diffusion Signal Behaviour Using a Fractional Dynamics Approach

Juan Parra-Robles1, Salma Ajraoui1, Jim M. Wild1

1University of Sheffield, Sheffield, United Kingdom

Diffusion of 3He gas in the lung has been shown to deviate from Gaussian behaviour. Cylinder model and diffusional kurtosis have been previously used to quantify non-Gaussian signals. In this work the diffusion stretched-exponential model is used as a new approach to model the non-Gaussian behaviour. The results obtained demonstrate that the anomalous diffusion stretched-exponential model fits well the behaviour of the 3He lung MR signal. This model can potentially provide valuable information about lung microstructure at different length scales.

                  2539.     Experimental Investigation of the Limits of Validity of the Physical Basis of a Method for in Vivo Lung Morphometry with 3He Diffusion MRI

Juan Parra-Robles1, Salma Ajraoui1, Martin H. Deppe1, Steven R. Parnell1, Jim M. Wild1

1Unit of Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

In this work, the limits of validity of physical basis of a model of 3He MR lung diffusion are investigated experimentally in simple geometric models. The experimental results have highlighted limitations of the cylinder model. Breakdown of the Gaussian phase approximation was experimentally demonstrated for gradient strengths commonly used in lung ADC experiments, as the localized diffusion regime is approached. The physical assumptions of the cylinder model are only valid if the localized diffusion regime and its neighboring intermediate regimes are avoided.

                  2540.     Exact Results for Diffusion Weighted MR on Branched Structures

Niels Buhl1,2, Sune Jespersen2

1Physics and Astronomy, University of Aarhus, Aarhus, Denmark; 2CFIN, University of Aarhus, Aarhus, Denmark

Diffusion-weighted MRI (DWI) employing long diffusion times can provide information on connectivity and topology in branching systems. We present an exact result for the diffusion propagator on a large class of metric networks (graphs), and subsequently derive an analytical expression for the signal attenuation in a PGSE diffusion experiment. We apply these results to a simple acinar model and demonstrate the sensitivity of DWI to an increasing number of collateral pathways.

                  2541.     Long-Time-Scale Hyperpolarized 3He and 129Xe Diffusion in Human Lungs: Experimental Measurements and Computer Simulation

Chengbo Wang1, Talissa A. Altes1, John P. Mugler, III1,2, Eduard E. de Lange1, Kai Ruppert1, William F. Hersman3,4, Isabel M. Dregely3, Iulian Ruset, 3,4, Stephen Ketel4, Sylvia Verbanck5

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Physics, University of New Hampshire, Durham, NH, United States; 4Xemed LLC, Durham, NH, United States; 5Respiratory Division, University Hospital UZ Brussel, Brussels, Belgium

Long-time-scale 3He and 129Xe diffusion was measured in human lungs and was found to strongly depend on the diffusion times. The computer simulation agreed well with experimental measurements using only the intra-acinar structure, suggesting that long-time-scale ADC was dominated by intra-acinar structure in the lung. The importance of the intra-acinar structure and collateral channels may vary with varying parameters such as tag wavelength.   Intra- and interacinar collateral channels can lead to considerable relative ADC increases, suggesting that noble gas diffusion may be sensitive to mild degree of collateral channels which may occur in early smoking related lung disease.

                  2542.     Imaging Morphometric Changes in the Human Pulmonary Acinus in Vivo Via 3He Diffusion MRI

Adam J. Hajari1,2, James D. Quirk2, Dmitriy A. Yablonskiy, 12, Alex L. Sukstanskii2, Mark S. Conradi1,2, Jason C. Woods, 12

1Physics, Washington University, St. Louis, MO, United States; 2Radiology, Washington University, St. Louis, MO, United States

3He diffusion MRI is used to study in-vivo morphological changes at the alveolar level in human lungs. We employ a 6 b-value diffusion pulse sequence for imaging at three different levels of inspiration.   An established mathematical model relating signal attenuation from the diffusion gradients to alveolar geometry is fit voxel-by-voxel to the diffusion images to determine average alveolar depth and alveolar duct radii at each of the three lung volumes.  On average a 50% increase in lung volume led to a 9% increase in average alveolar duct radius and a 22% decrease in average alveolar depth.

                  2543.     Measurement of the Diffusion of Hyperpolarized 129Xe in Human Lungs Over Short and Long Time Scales During One Breath Hold

Chengbo Wang1, John P. Mugler, III1,2, Eduard E. de Lange1, Kai Ruppert1, William F. Hersman3,4, Isabel M. Dregely3, Iulian Ruset, 3,4, Stephen Ketel4, Talissa A. Altes1

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Physics, University of New Hampshire, Durham, NH, United States; 4Xemed LLC, Durham, NH, United States

Regional ADC maps of hyperpolarized 129Xe in human lungs measured over both short and long time scales and with identical spatial registration during a single breath hold were acquired in 5 human subjects.  Measured 129Xe ADC values were about 10% of the corresponding previously reported 3He ADC values for both time scales, similar to the expected difference of 16% due to the differences in diffusivity of the gases.  The current SNR of 129Xe MRI is sufficient for diffusion MRI, and 129Xe diffusion MRI has been performed in healthy subjects and subjects with lung disease.

                  2544.     Relationship Between Lung Function and Lung Structure in Smokers as Measured by Hyperpolarized Helium-3 MRI

Chengbo Wang1, Talissa A. Altes1, John P. Mugler, III1,2, Eduard E. de Lange1, Robert M. Strieter3, Yun M. Shim3,4

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Medicine, University of Virginia, Charlottesville, VA, United States; 4Pulmonary and Critical Care, University of Virginia, Charlottesville, VA, United States

Short-time-scale (STS) and long-time-scale (LTS) helium-3 ADC values were measured in the lungs of smokers and found to be moderately correlated with %predFEV1, but poorly correlated with exercise stress testing, possibly because non-respiratory factors may significantly affect exercise capacity. STS helium-3 ADC values did not correlate with %DLCO while LTS ADC values were moderately correlated with %DLCO. These results support an association between lung microstructural alterations caused by cigarette smoking and functional changes in FEV1 and %DLCO, and suggest that LTS ADC is more sensitive than STS ADC in detecting early pulmonary injury.

                  2545.     Hyperpolarized 129Xe Diffusion MRI of the Lungs in Healthy Subjects and Chronic Obstructive Pulmonary Disease Patients

Suryanarayanan Sivaram Kaushik1, Zackary I. Cleveland1, Gary P. Cofer1, Gregory Metz2, Denise Beaver2, John Nouls1, Monica Kraft3, Jan Wolber4, H Page McAdams2, Bastiaan Driehuys1

1Center for In-Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Radiology, Duke University Medical Center, Durham, NC, United States; 3Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States; 4GE Healthcare, Amersham, United Kingdom

Apparent diffusion coefficient (ADC) MRI using hyperpolarized 3He has been established as a radiation free alternative to Computerized Tomography in evaluating pulmonary microstructure, but its use is limited in biomedical research applications due to its high cost and low availability. Recently, the success of HP 129Xe in showing sensitivity to alveolar microstructure changes in animals suggests that 129Xe, which is cheaper and more readily available, is also suitable for ADC measurements. Here, we discuss 129Xe ADC imaging results from healthy volunteers and COPD patients with early stage emphysema and show that 129Xe ADC imaging can successfully discriminate the two groups.

                  2546.     Quantitative Prediction of Lung Disease with Hyperpolarized Gas MRI – Validation in a Murine Model of Emphysema

Masaru Ishii1,2, Kiarash Emami2, John M. Woodburn2, Stephen J. Kadlecek2, Elaine Chia2, Jianliang Zhu3, Stephen Pickup2, Yi Xin2, Rahim R. Rizi2

1Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States

The sensitivity of two HP 3He MRI-based measurements, gas diffusivity and ventilation, to elastase-induced changes in a murine model of emphysema is studied in this work. The motivation is primarily the increasing interest in assessments of pulmonary disease models and assessments of therapeutic interventions in transgenic murine disease models, which require that functional and structural lung imaging techniques be translated to a smaller scale.  We present a predictive model for calculating the probability that a section of lung originated from a diseased animal.

                  2547.     Estimation of Rat Lung Surface to Volume Ratio and Xenon Diffusing Capacity Using Hyperpolarized 3He and 129Xe Gases

Matthew S. Fox1,2, Alexei Ouriadov1, William Dominguez-Viqueira1,3, Marcus Couch1,2, Giles E. Santyr1,3

1Imaging, Robarts Research Institute, London, Ontario, Canada; 2Physics and Astronomy Dept, University of Western Ontario, London, Ontario, Canada; 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada

Hyperpolarized 129Xe is a novel gaseous contrast agent which also dissolves in the lung parenchyma and blood compartments, offering an interesting palette of potential biomarkers of pulmonary disease. 129Xe signals from the dissolved compartments have different chemical shifts and can be selectively saturated and allowed to recovery as a function of delay time as in the chemically selective saturation recovery (CSSR) technique.  We collected CSSR data and 3D volumes from rat lungs in-vivo and explore both the Butler and Mansson model for estimations of surface to volume ratio, diffusing capacity and tissue transit time.

                  2548.     Anisotropic Nature of 3He Gas Diffusion in Mice Lungs

Emir Osmanagic1, Alexander L. Sukstanskii2, Mark S. Conradi3, James D. Quirk2, Dmitriy A. Yablonskiy2

1Electrical and Systems Engineering, Washington University, St. Louis, Misssouri, United States; 2Radiology, Washington University, St. Louis, Misssouri, United States; 3Physics, Washington University, St. Louis, MO, United States

Diffusion-attenuated MR signal of 3He gas in lungs demonstrate non-mono-exponential dependence on b-value. It was previously suggested that such behavior is a result of microscopically anisotropic but macroscopically isotropic nature of lung microstructure: diffusion in each airway is anisotropic, while distribution of airway axes directions is isotropic. Hypothetically such non-mono-exponential dependence would also be present in a system of multiple spherical compartments (mimicking alveoli) with a variety of sizes. Herein, we used experiments with three consecutive bipolar gradient pulses with orthogonal and parallel gradient orientations to discriminate between such two systems. Our result confirmed microscopically anisotropic hypothesis.

                  2549.     Quantitative Assessment of  Lung Microstructure in Healthy Mice Using Lung Morphometry with Hyperpolarized 3He Diffusion MRI

Emir Osmanagic1,2, Alexander L. Sukstanskii3, James D. Quirk3, Jason C. Woods3,4, Mark S. Conradi4, Dmitriy A. Yablonskiy3,5

1Electrical and Systems Engineering, Washington University, St. Louis, Misssouri, United States; 2Radiology, Washington University, St. Louis, MO, United States; 3Radiology, Washington University, St. Louis, Misssouri, United States; 4Physics, Washington University, St. Louis, MO, United States; 5Physics, Washington University, St. Louis, Misssouri, United States

Lung morphometry technique with hyperpolarized 3He allows quantification of lung geometrical parameters such as mean chord length Lm, surface-to-volume ratio S/V and density of alveoli. It was demonstrated that in humans, it provides results similar to direct morphological measurements. Two important modifications, however, are required to adopt this technique for studying lung microstructure in small animals – reduction in diffusion time and modification of theoretical relationship between diffusion MR signal and lung microstructural parameters. Herein we provided such modifications and demonstrated that measurements obtained with lung morphometry with hyperpolarized 3He MRI in mice are in agreement with literature data.

                  2550.     The Effect of Locally Administered Glucocorticoid Budesonide on Ovalbumin Exposed Rats Assessed by HP 3He MRI

Jelena Pesic1, Frank Risse1, Simon Young2, Jim Britt2, Ignacio Rodriguez3, Lars E. Olsson1

1DECS Imaging and Antibodies, AstraZeneca R&D, Mölndal, Sweden; 2Bioscience, AstraZeneca R&D, Charnwood, United Kingdom; 3Instituto de Estudios Biofuncionales, Universidad Complutense, Madrid, Spain

HP 3He ADC imaging was used to assess the effect of a glucocorticoid budesonide on inflammation in ovalbumin challenged rats. Four groups of animals were investigated: controls, vehicle treated, low and high dose budesonide treated. The ADC was significantly smaller in the vehicle group, indicating reduced airspace in the alveoli, possibly due to plasma leakage into the alveoli. Treatment with budesonide decreased inflammation as shown by significantly reduced eosinophil counts and higher ADC values than in the vehicle group.

                  2551.     Hyperpolarized Xenon-129 Dissolved-Phase Signal Dependence on Flip Angle and TR

Kai Ruppert1, Jaime F. Mata1, Isabel M. Dregely2, Talissa A. Altes1, G Wilson Miller1, Stephen Ketel3, Jeff Ketel3, Iulian C. Ruset, 2,3, F William Hersman2,3, John P. Mugler, III1

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH, United States; 3Xemed, LLC, Durham, NH, United States

Due to the large chemical shift difference between hyperpolarized Xe129 (HXe129) dissolved in lung tissue and in the alveolar air spaces it is feasible to image both compartments simultaneously, appearing side-by-side in the image, by using a suitable imaging bandwidth. The weighting of the dissolved-phase contrast can be shifted from exchange-site dominant to blood-pool dominant through an adjustment of the TR/FA combination of the acquisition. Thereby it is feasible to monitor and quantify the HXe129 gas transport processes throughout the pulmonary and cardiovascular system up to the aortic arch.

                  2552.     Hyperpolarized Xenon-129 Dissolved-Phase Signal Dependence on the Echo Time

Kai Ruppert1, Jaime F. Mata1, Isabel M. Dregely2, Talissa A. Altes1, G Wilson Miller1, Stephen Ketel3, Jeff Ketel3, Iulian C. Ruset3, F William Hersman2, John P. Mugler, III1

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH, United States; 3Xemed, LLC, Durham, NH, United States

Due to the large chemical shift difference between hyperpolarized Xe129 (HXe129) dissolved in lung tissue and in the alveolar air spaces it is feasible to image both compartments simultaneously, appearing side-by-side in the image, by using a suitable imaging bandwidth. By varying the TE of the image acquisition it appears to be  feasible to extract additional information about the regional distribution of the dissolved-phase sub-compartments, which might be strongly affected by pulmonary interstitial or vascular diseases. Prelimary results in alive and post mortem rabbits are presented.

                  2553.     Signal Dynamics During Dissolved-Phase Hyperpolarized 129Xe Radial MR Imaging of Human Lungs

Zackary I. Cleveland1,2, Gary P. Cofer1,2, Gregory Metz3, Denise Beaver3, John Nouls1,2, Sivaram Kaushik1,2, Monica Kraft3, Jan Wolber4, Kevin T. Kelly5, H Page McAdams2, Bastiaan Driehuys1,2

1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Radiology, Duke University Medical Center, Durham, NC, United States; 3Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States; 4GE Healthcare, Amersham, United Kingdom; 5Radiation Oncology, Duke University Medical Center, Durham, NC, United States

It is now possible to directly image HP 129Xe dissolved in pulmonary gas exchange tissues of humans. Dissolved image intensity is dominated by relaxation, RF attenuation, and diffusive replenishment of dissolved 129Xe magnetization, which are influenced by pulmonary structure and physiology. Here, we develop a closed-form mathematical model of dissolved 129Xe magnetization dynamics during 3D radial imaging. Model predictions agree well with observations and can be used in image optimization. Because radial images acquire k-zero in each view, the model also allows dynamic information to be extracted from raw image data and may provide insights into global lung physiology.

                  2554.     Lung Microstructure Changes in a Rabbit After Elastase Instillation as Detected with Multiple Exchange Time XTC (MXTC)

Isabel Dregely1, Kai Ruppert2, Jaime F. Mata2, Talissa A. Altes2, Jeff Ketel3, Iulian C. Ruset3, Steve Ketel3, G. Wilson Miller2, John P. Mugler III2, F. W. Hersman1,3

1Physics, University of New Hampshire, Durham, NH, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States; 3Xemed LLC, Durham, NH, United States

The purpose of this work is to investigate the ability of 3D multiple exchange time xenon polarization transfer contrast (MXTC) MRI to detect changes in lung microstructure following the instillation of elastase into a rabbit lung. 3D MXTC is an extension of the XTC technique, which allows the calculation of the regional septal wall thickness and the tissue-to-alveolar-volume ratio. We observed an increase in the global mean of tissue thickness and relative tissue volume and identified regions of abnormal lung microstructure in the rabbit lung post-elastase instillation most likely due to an initial severe inflammatory response.

                  2555.     The Structural Response of the Compliant Lung to Different Ventilation Volumes Assessed by Multiple Exchange Time Xenon Transfer Contrast (MXTC)

Isabel Dregely1, Iulian C. Ruset2, Jeff Ketel2, Steve Ketel2, Jaime F. Mata3, Talissa A. Altes3, G. Wilson Miller3, John P. Mugler III3, F. W. Hersman1,2, Kai Ruppert3

1Physics, University of New Hampshire, Durham, NH, United States; 2Xemed LLC, Durham, NH, United States; 3Radiology, University of Virginia, Charlottesville, VA, United States

We investigated the response of rabbit lungs to different lung ventilation volumes using 3D multiple-exchange time xenon polarization transfer contrast (MXTC) MRI. From the subsequently fitted exchange time constant of the xenon exchange between alveolar air spaces and the surrounding septal walls, the tissue thickness can be calculated. The long exchange time limit allows calculation of the tissue-to-alveolar volume ratio. We observed increased tissue-to-alveolar volume ratio in posterior partitions and decreased septal wall thickness in anterior partitions at low lung volumes. At high ventilation volumes these differences disappear.

                  2556.     Theoretical Model for XTC (Xenon Transfer Contrast) Experiments with Hyperpolarized 129Xe

Mirko I. Hrovat1, Iga Muradian2, Eric Frederick3, James P. Butler4, Hiroto Hatabu2, Samuel Patz2

1Mirtech, Inc., Brockton, MA, United States; 2Radiology, Brigham and Women's Hospital, Boston, MA, United States; 3Dept. of Physics, University of Masachusetts at Lowell, Lowell, MA, United States; 4Harvard School of Public Health, Boston, MA, United States

A theoretical model is presented to understand the XTC experiment with hyperpolarized 129Xe for arbitrary flip angle. The model is flexible in that different dissolved state diffusion models may be incorporated. The model also illustrates fundamental differences between CSSR and XTC experiments. It is clear that no single exchange time value dominates the time evolution of the XTC signal. It is demonstrated that the XTC90 experiment (employing 90° flips instead of 180°) should generate results similar to CSSR experiments.

                  2557.     Lung Inflation State Dominates Over Intrapulmonary PO2 Regarding T2* of 3He in Human Lungs

Martin H. Deppe1, Salma Ajraoui1, Helen Marshall1, Jim M. Wild1

1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom

This work investigates the influence of O2 on the T2* of hyperpolarized 3He in human lungs. To separate the effect of O2 from the known lung inflation dependence, T2* maps were obtained at expiration and full inspiration, both at baseline breathing air and after 4 min of pure O2. It is found that the effect of lung inflation dominates over any potential O2 effect, which is proposed to be due to a combination of motional narrowing and the fact that 3He is distributed over the whole alveolus, while 1H spins are confined to the interfaces, where susceptibility gradients are strongest.

                  2558.     Motion-Corrected PO2 Mapping in Human Lungs Using Hyperpolarized Xe-129 MRI

G. Wilson Miller1, John P. Mugler III1, Talissa A. Altes1, Isabel Dregely2, Iulian Ruset3, Steve Ketel3, Jeff Ketel3, William F. Hersman2,3, Kai Ruppert1

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH; 3Xemed LLC, Durham, NH

Lung pO2 mapping using hyperpolarized Xe-129 was performed in 6 healthy volunteers and 4 disease patients. An image registration algorithm was used to correct for subject motion during the breath hold acquisition.

                  2559.     An Integrated Small-Animal Ventilator and Recycling System for Small-Animal Hyperpolarized Gas MRI

John C. Nouls1, Manuel Fanarjian2, Bastiaan Driehuys1,3

1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Biomedical Engineering, Duke University, Durham, NC, United States; 3Radiology, Duke University Medical Center

We present a constant-volume small-animal ventilator that offers precise control of gas delivery, permits high-resolution hyperpolarized gas imaging, and captures the exhaled mixture containing 3He or 129Xe for recycling. The captured gas is compressed by a piston and stored in a cylinder to be sent for re-purification. The same ventilator can ventilate different small animals, simply by changing flow constrictors. The ventilator is inexpensive to duplicate and only uses off-the shelf components. By recapturing exhaled gas, it alleviates some of the costs associated with HP gas imaging.

                  2560.     Hyperpolarized Noble Gas MR Imaging SNR Comparison Between 73.5 MT and 3 T in Rat Lung

William Dominguez-Viqueira1,2, Matthew S. Fox, 1,3, Giles E. Santyr2,4

1Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada; 4Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada

The maximum SNR in Hyperpolarized Noble Gas (HNG) MR imaging of rodent lung is expected to be at high fields (>3T). However, SNR improvements of up to 300% have been demonstrated in rat lung at 73.5mT using Litz-wire coils. In this work the SNR for HNG MRI of rat lung was investigated theoretically and in vivo, using multi-turn Litz-wire coils at 73.5mT and compared to images obtained at 3T using 129Xe and 3He. The use of Litz-wire coils significantly reduces the advantage (from factor ten to a factor of two) of using high fields for HNG imaging of rat lungs.

                  2561.     Quantitative Assessment of Alveolar Recruitment with Hyperpolarized Gas MRI

Kiarash Emami1, Masaru Ishii2, Stephen J. Kadlecek1, Jianliang Zhu3, Stephen Pickup1, Yi Xin1, Puttisarn Mongkolwisetwara1, Harrilla Profka1, Rahim R. Rizi1

1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States; 3Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States

This study evaluates the preliminary use of HP gas diffusion MRI to assess alveolar recruitment dynamics in a healthy rat model.  After a period of ventilation at zero positive end-expiratory pressure (PEEP), recruitment was studied at elevated PEEP and constant tidal volume.  After recruitment, it was found that regional ADC values initially diminished and consistently recovered with the removal of elevated PEEP.  It is therefore proposed that before recruitment, accumulated alveolar collapse causes the over-extension of active alveoli (high ADC); after recruitment, the fixed tidal volume is shared by the greater number of recruited alveoli (corresponding to decreased ADC).

                  2562.     Alveolar Gas Diffusion MRI as a Function of Pulmonary Pressure

Kiarash Emami1, Stephen J. Kadlecek1, Yi Xin1, Puttisarn Mongkolwisetwara1, Harrilla Profka1, Stephen Pickup1, Jianliang Zhu2, Masaru Ishii3, Rahim R. Rizi1

1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States

In this work, we evaluate the use of HP gas ADC measurements to assess the positive end-expiratory pressure (PEEP) dependence of alveolar recruitment in a healthy rat model.  By maintaining a constant tidal volume, ADC can be decoupled from volume dependence and thus considered a measurement of average alveolar size.  In general, it was found that higher ADC values correspond with large PEEP.  Additionally, at any given PEEP, the end-inhale ADC value is larger than the end-exhale ADC value, supporting the theory that in low-recruitment conditions (large numbers of collapsed alveoli), active alveoli are over-inflated (yielding high ADC).

                  2563.     Quantitative Assessment of Idiopathic Pulmonary Fibrosis with Hyperpolarized Gas MRI

Michael J. Stephen1, Kiarash Emami2, John M. Woodburn2, Elaine Chia2, Stephen J. Kadlecek2, Jianliang Zhu3, Masaru Ishii4, Milton Rossman1, Benjamin Pullinger2, Stephen Pickup2, Rahim R. Rizi2

1Department of Pulmonary and Critical Care, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Surgery, VA Medical Center, Philadelphia, PA, United States; 4Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States

This study demonstrates the first attempt to use hyperpolarized gas MR images of lung ventilation and apparent diffusion (ADC) in an animal model of interstitial lung disease.  The efficacy of hyperpolarized 3He MRI metrics in assessing idiopathic pulmonary fibrosis (IPF) was evaluated in a bleomycin rat model.  Results showed that fractional ventilation 3 weeks after bleomycin administration was significantly lower than in the control animals, and ADC measurements followed similar trends.  Hyperpolarized gas MRI is a promising diagnostic for IPF and an improvement over current diagnostics in its regional sensitivity and benignancy.

                  2564.     Regional Pulmonary Pressure Over Volume Curves of  the Rat Lung Measured by Polarized 3He Magnetic Resonance Imaging

Angelos Kyriazis1,2, Ignacio Rodriguez1,2, Jose-Manuel Perez-Sanchez3, Lars E. Olsson4, Jesus Ruiz-Cabello1,2

1Universidad Complutense de Madrid, Instituto de Estudios Biofuncionales, Madrid, Spain; 2CIBER de Enfermedades Respiratorias, Spain; 3Orsay and Kremlin-Bicetre, U2R2M, Paris, France; 4DECS Imaging, AstraZeneca R&D, Mölndal, Sweden

A method to estimate regional lung volume over time based on spin-density 3He images is presented. Combining this with the tracheal pressure, regional volume over pressure is appraised. The static ROI are the left and the right lobe of the lung. Physiological parameters were calculated for the two ROI and for the whole lung. The method is proven reproducible because the measurements of the ROI of the same animal as well as the measurements of different animals agreed satisfactorily. The method may differentiate not only healthy from diseased animals but also healthy from diseased areas of the lung.

                  2565.     In Vivo Comparison of 2D and 3D T2* in the Rat Lung Using Hyperpolarized Helium-3 MRI at 1.5 T

Kyle Hill1,2, José-Manuel Pérez-Sánchez2, Roberta Santarelli2, Mathieu Sarracanie2, Pascal Hagot2, Marlies Friese2, Xavier Maître2, Luc Darrasse2

1University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Imagerie par Résonance Magnétique Médicale et Multimodalité (UMR 8081), Univ Paris-Sud, CNRS, Paris, Le Kremlin-Bicêtre, France

The T¬2* of hyperpolarized helium-3 in the lungs has shown promise in characterizing lung microstructure due to its sensitivity to local gradients caused by gas-tissue interfaces, whose abundance per unit volume changes with lung inflation and pathological modification. Despite the lung’s three-dimensional structure, most measurements of helium-3 T¬2* have been performed using projection imaging which neglects the complex microstructure’s effects. This work uses five rats in vivo to compare the T2* in a projection image with 3D imaging and shows that 3D is necessary to detect statistically different local phenomena that may not be apparent in projection imaging.

                  2566.     Gravity Dependent Ventilation of Rats Measured by Hyperpolarised Helium MRI and Electric Impedence Tomography

Marlies Elly Joy Friese1, Kimble R. Dunster, 12, Gary J. Cowin1, Deming Wang1, Graham Galloway1, John Fraser3,4, Andreas Schibler, 4,5

1Centre for Magnetic Resonance, The University of Queensland, Brisbane, Queensland, Australia; 2Medical Engineering Research Facility,, Queensland University of Technology, Brisbane, Queensland, Australia; 3Paediatric Intensive Care Unit,, Mater Children’s Hospital, Brisbane, Queensland, Australia; 4Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; 5Paediatric Intensive Care Unit, Mater Children’s Hospital, Brisbane, Queensland, Australia

Gravity-dependent ventilation distribution was investigated in using both hyperpolarised helium-3 magnetic resonance imaging (HP3He MRI) and electrical impedance tomography (EIT). Time averaged EIT data and HP3HeMRI images of apnoea showed ventilation distribution in rats to be gravity dependent, whereas regional filling characteristics are dependent on anatomy. HP3He MRI and EIT data agree where they can be compared. HP3He MRI provides data on real geometry which EIT cannot as EIT tomograms are reconstructed to a circular image. Dynamic imaging of the breathing cycle with HP3He is still needed to make a full comparison of the two methods.

                  2567.     Respiratory Impedance in a Mouse Model of Asthma Using Hyperpolarized 3He MR Imaging

Suryanarayanan Sivaram Kaushik1, John Nouls1, Erin Potts2, Zackary Cleveland1, W Michael Foster2, Bastiaan Driehuys1

1Center for In-Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States

The broncho-constriction and inflammation associated with asthma contributes to increased airway impedance. This impedance is typically measured using global respiratory mechanics techniques such as FlexiVent. However, the time course of broncho-constriction can also be directly visualized using hyperpolarized (HP) 3He MRI. This imaging-based technique provides a time-dependent method for quantifying central airway impedance and may be useful to assess the regional contributions to globally measured impedance. Here, we discuss the method we used in obtaining the upper airway impedance during a Methacholine (Mch) challenge, in a mouse model of asthma.

                  2568.     Relaxation of Hyperpolarized 129Xe in a Flexible Gas Reservoir

Harald E. Möller1,2, Zackary I. Cleveland2, Laurence W. Hedlund2, Bastiaan Driehuys2

1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States

In experiments involving repeated deliveries of hyperpolarized (HP) gas, the delivered magnetization is not constant due to unavoidable relaxation during HP gas storage. Moreover, the spin-lattice relaxation time, T1R, inside flexible plastic bags, which often serve as HP gas reservoirs, is not constant. The change of T1R of HP 129Xe in a deflating bag can be quantitatively described by a model based on simple spherical geometry and the kinetic theory of gases to account for relaxation mechanisms in the bulk gas and on the container walls. Results might be used for optimizing signal utilization and improving the point-spread function.

                  2569.     Hyperpolarized 3He Image Feature Analysis in Asthmatics

Nicholas James Tustison1, Talissa A. Altes2, Gang Song1, Eduard E. de Lange2, John P. Mugler III2, James C. Gee1

1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States

We analyze features extracted from hyperpolarized helium-3 ventilation images in asthmatic and normal populations and quantify their discriminatory abilities in characterizing clinical diagnosis relative to spirometric features.

                  2570.     Retrospective Bias Correction of Hyperpolarized 3He MRI of the Lung

Nicholas James Tustison1, Talissa A. Altes2, G. Wilson Miller2, Eduard E. de Lange2, John P. Mugler III2, James C. Gee1

1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States

We present an open source bias correction algorithm based on the popular N3 algorithm and demonstrate its superior performance for nonuniform intensity correction in hyperpolarized helium-3 lung images.

                  2571.     Hyperpolarized 3He Magnetic Resonance Image Registration Tools for Longitudinal and Multi-Modality Studies

Lindsay Mathew1,2, Usaf Aladl1, Aaron Fenster1,2, Grace Parraga1,2

1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

Hyperpolarized 3He MRI has shown promise as a treatment planning tool for lung cancer. Current barriers to the application of this technology include a lack of accurate image registration techniques. Registration of longitudinally acquired 3He MRI scans and 3He MRI to CT will allow for both detection of regional changes in lung function, and determination of ventilation defect pathology. In this study accuracy and variability of 3He MRI registration techniques were evaluated from a dataset consisting of subjects scanned longitudinally at our center. The Fiducial Localization Error and Fiducial Registration Error were evaluated as metrics of registration accuracy and precision.

                  2572.     Quantitative Evaluation of Hyperpolarized Gas Retention in the Lungs During Time Resolved 3D MRI

Jionghan Dai1, Eric Peterson2, James H. Holmes3, Sean B. Fain1,4

1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States; 3Applied Science Lab, GE Healthcare, Madison, WI, United States; 4Radiology, University of Wisconsin - Madison, Madison, WI, United States

This work seeks to provide a quantitative regional measure of gas retention in the lung. A 3D multi-echo projection acquisition is used, accompanied with an iterative HYPR reconstruction to provide a time resolved 3D image series. Post exhalation images are used to generate quantitative maps of gas retention. To summarize, this work presents potential new methods to characterize the gas retention under forced exhalation using hyperpolarized noble gas MRI.

                  2573.     B1 Self-Calibration for Artifact Removal in Radial Hyperpolarised 3He Lung Imaging

Helen Marshall1, Salma Ajraoui1, Martin Deppe1, James M. Wild1

1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

In hyperpolarised 3He lung MRI the transverse signal decays with each RF excitation, imposing a k-space filter on the acquired data.  For radially acquired data this filter causes streaking, angular shading and loss of spatial resolution in the images.  Radial acquisition samples the centre of k-space with every projection, so tracking the signal decay.  The inverse of this decay function was used to retrospectively compensate the data leading to improved image quality.  The average flip angle per slice was calculated from the radial data and found to correspond well with conventional flip angle maps providing a means of B1 self-calibration.

                  2574.     Performance of Three Transmitter Calibration Methods for Hyperpolarized Gas MRI in the Presence of B0 and B1 Inhomogeneity

Kun Qing1, Grady Wilson Miller2, John Philip Mugler, 12

1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Department of Radiology, University of Virginia, Charlottesville, VA, United States

A low-flip-angle, phase-based method for calibrating the transmitter voltage for hyperpolarized gas MRI has been presented in previous studies. This work introduces two optimized versions of the phase-based method, and evaluates their performance in the presence of B0 and B1 inhomogeneities compared to that for an amplitude-based method. Results show that the accuracy of all three methods is affected by significant B1 inhomogeneity; for significant B0 inhomogeneity, the amplitude-based method is robust while the phase-based methods are very sensitive, particularly at relatively low flip angles.

                  2575.     Proton Acquisition with Variable Flip Angle to Simulate and Optimized Hyperpolarized 3He MRI with Parallel Acquisition

Julien Rivoire1, Maxin Terekhov1, Laura Maria Schreiber1

1Department of Diagnostic and Interventional Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center, Mainz, Germany

To employ the scanner’s software computational capabilities and to simulate the complete measurement process without using expensive hyperpolarized gas, we developed the dedicated 1H MRI acquisition protocol using variable flip angle pulse sequence to simulate hyperpolarized magnetization decay. The protocol was used to study the effect of different space sampling ordering on images acquired with parallel acquisition techniques. Via the calculation of point-spread-function, the effects of the trajectories were quantitatively compared.

                  2576.     Hyperpolarized Steady-State Free Precession with Variable Flip Angles (BSSFP-VFA)

Martin H. Deppe1, Jim M. Wild1

1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom

In imaging of hyperpolarized nuclei, balanced Steady-State Free Precession (bSSFP) sequences present a high SNR alternative to the most commonly used Spoiled Gradient Echo (SPGR) sequences. Because hyperpolarized nuclei are not at thermal equilibrium, the longitudinal magnetization does not recover during an imaging experiment, but decays to a negligible value with T1. This work presents analytical expressions for variable flip angle schedules that maintain constant transverse magnetization, optimizing the effective k-space filter imposed by decay of hyperpolarization, and hence reducing image blurring. The validity of the obtained expression is demonstrated in phantom experiments.

                  2577.     High-Efficiency Continuous Production of Hyperpolarized 129Xe Using Line-Narrowed Diode Lasers and Optimized Cell for High Concentration of Optically Pumped Rubidium

Mineyuki Hattori1, Takashi Hiraga2, Morio Murayama3, Norio Ohtake3

1Photonics, AIST, Tsukuba, Ibaraki, Japan; 2Photonics, AIST, Ikeda, Osaka, Japan; 3Toyoko Kagaku Co., Ltd., Kawasaki, Kanagawa, Japan

A compact flow-through-type apparatus for the high-efficiency continuous production of hyperpolarized 129Xe using line-narrowed diode lasers and an optimized cell for obtaining a higher rubidium vapor concentration at a higher temperature (~220 oC) was developed.

                  2578.     McConnell-Bloch Modeling of HyperCEST with Xenon Biosensors

Richard Matthew Ramirez1, Todd K. Stevens1, Monica A. Smith2, David E. Wemmer1, Alexander Pines1

1Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States; 2Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA, United States

The McConnell-Bloch equations were modified to account for the use of hyperpolarized xenon, and then applied to fit experimental data obtained from hyperCEST experiments in which Xe exchanges into and out of a supramolecular host.  A variety of physical parameters were tested and rate constants for the reversible exchange were determined, which are important in determining the amount of contrast generated from these agents.

                  2579.     Metastability Exchange Optical Pumping of 3He at 1.5T for a In-Situ Polariser

guilhem Collier1, Anna Nikiel1, Tadeusz Palasz1, Bartek Glowacz1, Mateusz Suchanek2, Zbigniew Olejniczak3, Tomasz Dohnalik1

1M. Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Malopolska, Poland; 2Department of Physics, Agricultural University, Krakow, Poland; 3Institute of Nuclear Physics, Polish Academy of Sciences, Krakow

The feasibility of building an in situ high field polariser of 3He using the Metastability Exchange Optical Pumping (MEOP) technique is studying here. The first results obtained with different closed cells of 3He show the possibility to produce hyperpolarised gas up to 30% at 267 mbar and 67% at 32 mbar with a volume nagnetization production never obtained yet.

                  2580.     Pressure Dependent Signal Enhancement in Hyper-CEST

Wolfgang Kilian1, Lorenz Mitschang1, Christian Freund2, Andreas Schlundt2

1Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany; 2Leibnizinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany

The so called hyper-CEST method promises tremendous potential on molecule-specific MR imaging using hyperpolarized 129Xe caged in functionalized cryptophane cages. Here we present a model which allows for an optimization of the hyper-CEST sensitivity in biosensor applications, by variation of the xenon concentration in the solution. To evaluate the model we have performed hyper-CEST measurements on samples with 5 μM and 0.5 μM biosensor concentrations and varied the dissolved xenon concentration. This comparison shows that 50 nM biosensor concentrations should be detectable within a volume of 1 ml with high sensitivity.

Hepato-Biliary & Liver

Hall B                        Monday 14:00-16:00                                                                                                  

                  2581.     Fat Content Quantification Errors Using Multiple Gradient Echo Imaging: A Phantom and Simulation Study

Benjamin Leporq1, Hélène Ratiney1, Sophie Cavassila1, Frank Pilleul2, Olivier Beuf1

1Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Villeurbanne, France; 2Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France

In the past decade, the incidence increase of obesity, diabetes and lipid metabolism disorders involved an epidemic increase of Non-Alcoholic Fatty Liver Diseases (NAFLD) in the occidental population. Because NAFLD can evolve into Non-Alcoholic Steato-Hepatitis (NASH) and may lead to liver fibrosis up to cirrhosis, a clinical follow-up of NAFLD would be very valuable. This work investigated fat content quantification error using different models based on multiple gradient echo imaging and presents some computer simulations, phantom study and examples of in-vivo application. Multiple gradient echo acquisitions with two different flip angles associated with a model correcting for T1 saturation and T2* decay appears to be a simple but effective non-invasive method available on all clinical systems to monitor patients with chronic liver diseases.

                  2582.     Improvements in Hepatic Stiffness Assessment with 3-D/3-Axis MR Elastography

Meng Yin1, Kevin J. Glaser1, Jun Chen1, Jayant A. Talwalkar2, Armando Manduca1, Richard L. Ehman1

1Department of Radiology, Mayo Clinic, Rochester, MN, United States; 2Division of Gastroenterology, Mayo Clinic, Rochester, MN, United States

One advantage of liver MR elastography (MRE) over biopsy or ultrasound-based transient elastography is its ability to reduce sampling errors by measuring liver stiffness over a large portion of the liver. While existing 2-D or localized approaches yield valid results in a substantial part of the volume, a full 3-D/3-axis wave analysis is required for valid measurements of stiffness throughout the entire liver. This investigation compares a 2-D and a 3-D approach for liver MRE and demonstrates that 3-D MRE analysis improves the homogeneity of hepatic stiffness estimates.

                  2583.     A Software Tool for Volume Registration and Atlas-Based Segmentation of Human Fat-Water MRI Data in Longitudinal Studies

Anand Arvind Joshi1, H Harry Hu2, Michael Goran3, Richard Leahy2, Arthur Toga1, Krishna Nayak2

1Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States; 2Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles; 3Keck School of Medicine, University of Southern California, Los Angeles, CA

Obesity continues to be a worldwide epidemic. Accurate quantification of subcutaneous and visceral adipose tissue depot volumes and the degree fat infiltration in the liver, the pancreas, skeletal muscle, and the kidneys, are important endpoints in determining the efficacy of therapeutic and interventional measures against obesity.  For example, in longitudinal studies, measures are taken at multiple time points in each subject to determine the effects of diet, exercise, lifestyle modifications, and surgery, on fat quantity and distribution. In this work, we present an automated atlas-based tool for performing 3D volume registration and segmentation of abdominal adipose tissue depots and organs.

                  2584.     Orthotopic Liver Transplantation:  MRI Based Measurement of Donor Graft Steatosis, Graft Performance and Outcome.

David John Lomas1, Richard T. Black1, Andrew J. Patterson1, Kieren G. Hollingsworth1, Susan Davies2, Graeme J. Alexander3, Mike E. Allison3, Neville V. Jamieson4, Alex E. Gimson3, Raaj K. Praseedom4, Chris J. Watson4

1Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 2Pathology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 3Hepatology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 4Surgery, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

The results of rapid MRI based measurement of donor graft steatosis immediately prior to orthotopic liver transplantation in 49 patients were correlated with surgical and histopathology estimates, first week graft performance and 3 and 12 month outcomes. MR measurements correlated significantly with the other steatosis estimates but did not correlate with early serum performance markers. Both MRI and pathology estimates indicated significantly increased graft steatosis in those grafts failing at 3 months but not at 12 months. Such MRI based measurements may be a valuable tool for further investigating the impact of graft steatosis on transplant outcomes.

                  2585.     Effect of Intravenous Gadolinium on Estimation of Liver Stiffness with MR Elastography

Sudhakar Kundapur Venkatesh1, Lynette Li San Teo1, Bertrand Wei Leng Ang1, Richard L. Ehman2

1Diagnostic Imaging, National University Health System, Singapore, Singapore; 2Radiology, Mayo Clinic, Rochester, MN, United States

MR Elastography is currently the most accurate non-invasive technique for assessment of liver fibrosis. In this study, we investigated whether administration of gadolinium for routine MRI studies affects the stiffness values estimated. Our study results show that intravenous gadolinium does not affect stiffness values estimation and diagnostic performance of MRE for detection of liver fibrosis.

                  2586.     Non-Invasive Detection of Liver Fibrosis- A Comparison Study Between MR Elastography and Diffusion Weighted MR Imaging

Sudhakar Kundapur Venkatesh1, Lynette Li San Teo1, Bertrand Wei Leng Ang1, Seng Gee Lim2, Aileen Wee3

1Diagnostic Imaging, National University Health System, Singapore, Singapore; 2Gastroenterology and Hepatology, National University Health System, Singapore, Singapore; 3Pathology, National University Health System, Singapore, Singapore

Liver biopsy is the gold standard for diagnosis of liver fibrosis, however has related risks and costs. A non-invasive marker of liver fibrosis is therefore desirable. Currently MRE and DWI are most promising tests for detection of liver fibrosis without the use of gadolinium based contrast agents. We performed a study to compare the performance of DWI and MRE for detection of liver fibrosis. Our study shows that MRE is more accurate than DWI for detection of all grades of fibrosis and in particular clinically significant fibrosis.

                  2587.     7T Human Liver Imaging Using Microstrip Surface Coil

Yong Pang1, Bing Wu2, Chunsheng Wang2, Daniel Vigneron2,3, Xiaoliang Zhang2,3

1Radiology and Biomedical imaging, University of California San Francisco, San Francisco, CA , United States; 2Radiology and Biomedical imaging, University of California San Francisco, San Francisco, CA, United States; 3 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco & Berkeley, CA, United States

MRI can provide clinically-valuable images for hepatic diseases and has become the most accurate noninvasive method in evaluating liver lesions. With the development of high and ultrahigh field MRI, liver images may be acquired within breath-hold period using very short TE, essentially reducing scanning time and motion artifacts. However, B1 variation can cause significant problems at high field. In this work, T1 weighted human liver images are acquired using a fast gradient echo sequence and a λ/2 microstrip surface coil on GE whole body 7T scanner. Preliminary data demonstrates the feasibility of human liver imaging at 7 Tesla.

                  2588.     Assessment of Chemical Exchange Saturation Transfer Effects in Liver Tissue at 7T

Kejia Cai1, Mohammad Haris1, Anup Singh1, Santosh Gaddam1, Dania Daye1, Kalli Grasley1, Gerald Zsido II1, Hari Hariharan1, Ravinder Reddy1

1CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

The objective of the present study was to determine the chemical exchange saturation transfer (CEST) effects of water signal in normal and pathological liver samples on 7T MR clinical scanner, ex-vivo. In all liver tissue samples, the z-spectra showed a dip around ~2.75ppm downfield to the bulk water resonance, suggestive of exchangeable proton at this frequency. The pathological tissues showed significantly higher CEST contrast compared to normal. We are hypothesizing that the formation of liver fibrosis in various disease conditions may be expressing metabolites with exchanging groups resonating at the observed CEST frequency.

                  2589.     Cost Function Guided Image Based B0 Shimming at 3T for Efficient Fat Suppression in Liver and Prostate Imaging

Jeroen Cornelis Siero1, Marielle E. Philippens2, Arjan Willem Simonetti3, Johannes Marinus Hoogduin1, Peter R. Luijten4

1Brain Division, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiotherapy, University Medical Center Utrecht; 3Philips Healthcare, Best, Netherlands; 4Radiology, University Medical Center Utrecht, Utrecht, Netherlands

The potential of cost function guided shimming was shown at 3T for finding optimal shim fields that minimize B0 inhomogeneities on a user-defined region of interest while confining the B0 inhomogeneities outside this ROI. Experiments and simulations using the hybrid shimming approach show the possibility to control frequency selective fat suppression in abdomen and pelvic imaging while maintaining good B0 homogeneity in the region of interest.

                  2590.     Reduction in Dielectric Shading in Liver on Clinical 3T Parallel Transmission MR System

Trevor Andrews1, Jimmy S. Ghostine2, Jay V. Gonyea2, George M. Ebert2, Steven P. Braff3, Christopher G. Filippi3

1Philps Healthcare, Cleveland, OH, United States; 2Radiology, Fletcher Allen Health Care-UVM, Burlington, VT, United States; 3Radiology, Fletcher Allen Health Care-University of Vermont School of Medicine, Burlington, VT, United States

Dielectric shading artifacts impair image quality for body applications at 3T and hamper clinical acceptance of 3T body imaging. Parallel radiofrequency (RF) excitation, an application of parallel imaging to transmission, at 3T, reduces dielectric shading by adjustment of RF transmission signals enabling RF “shimming” There is the added benefit of more uniform specific absorption ratio (SAR), and shorter acquisition times. Our purpose was to quantitatively validate a novel acquisition method for reducing dielectric shading using parallel transmission techniques in clinical 3T abdominal MRI. In most cases, shading artifact was nearly eliminated, and with B1 shimming this was significantly lower.

                  2591.     Continuously Moving Table MR Imaging at 3T: A Comparison to 1.5T

Ute Ariane Ludwig1, Maxim Zaitsev1, Sandra Huff1

1Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany

Since the introduction of continuously moving table (CMT) imaging, metastases screening can easily performed in the whole body on clinical routine scanners. In this abstract, we want to demonstrate the feasibility of CMT techniques at higher field strengths. Clinical relevant imaging sequences have been adapted for imaging at 3T and evaluated on volunteers. Signal-to-noise ratio and contrast-to noise ratio have been compared to 1.5T. Future studies will combine CMT protocols for metastases screening with other MR modalities like perfusion imaging or spectroscopy, which benefit from the signal increase at higher field strengths.

                  2592.     Flip Angle Optimization with Hepatobiliary Contrast Agents at 3T

Sharon Lisa D'Souza1, Alex P. Frydrychowicz1, Karl K. Vigen1, Scott K. Nagle1, Scott B. Reeder2

1Radiology, University of Wisconsin, Madison, WI, United States; 2Radiology, Medical Physics, Biomedical Engineering, and Medicine, University of Wisconsin, Madison, WI, United States

Gadolinium based contrast agents Gd-EOB-DTPA and Gd-BOPTA have hepatobiliary excretion and tremendous utility for liver lesion characterization and biliary imaging with T1 weighted imaging. Unfortunately, most T1 weighted sequences are not optimized for maximizing CNR in delayed phase hepatobiliary imaging. The purpose of this study was to perform flip angle optimization at 3.0T for delayed hepatobiliary phase imaging as part of a cross-over study comparing Gd-EOB-DTPA and Gd-BOPTA. Data show that imaging at 40-45° FA with 0.05mmol/kg Gd-EOB-DTPA at 20 minutes and 20-25° FA with 0.1mmol/kg Gd-BOPTA provides optimal CNR behavior to visualize the liver and bile ducts.

                  2593.     Effects of a Single Intravenous Dose of Estradiol-17β D-Glucuronide on Biliary Excretion: Assessment with Gadoxetate DCEMRI

Jose Ulloa1, Simone Stahl2, Carsten Liess1, Jonathan Bright3, Angela McDermott2, Neil Woodhouse1, Jane Halliday1, Arvind Parmar1, Guy Healing2, Gerry Kenna2, Andrew Holmes1, Hervé Barjat1, John Waterton1, Paul Hockings1

1Translational Sciences, Astrazeneca, Macclesfield, Cheshire, United Kingdom; 2Safety Assessment, Astrazeneca, Macclesfield, Cheshire, United Kingdom; 3Discovery Statistics, Astrazeneca, Macclesfield, Cheshire, United Kingdom

Cholestasis is an important mechanism that can result in drug induced liver injury, a recurrent cause of attrition of new drug candidates. In rats, transporters Oatp1 and Mrp2 mediate liver uptake and clearance of gadoxetate, a hepatobiliary contrast agent used to characterise focal liver lesions. Estradiol-17β D-glucuronide (E217G) induces acute but transient cholestasis in rats through impairment of Mrp2 and Bsep function. The aim of this work was to assess whether characterisation of the kinetics of gadoxetate excretion can detect transient cholestasis induced by E217G. Results suggest this method can be used to investigate inhibition of transporters mediating biliary excretion.

                  2594.     3D-Liver Perfusion MR Imaging with MS-325 Blood Pool Contrast Agent to Evaluate Liver Fibrosis

Benjamin Leporq1, Olivier Beuf1, Denis Grenier1, Frank Pilleul2

1Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Villeurbanne, France; 2Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France

Liver fibrosis is an important cause of mortality and morbidity in patients with chronic liver. A non invasive technique to perform an early detection and a clinical follow-up of liver fibrosis is still needed. The objectives of this study was to evaluate estimated-perfusion parameters based on 1.5T-MR dynamic acquisition with the MS-325 paramagnetic blood pool agent for liver fibrosis diagnosis in comparison with histological findings. Dynamic 3D MRI was performed with a continuous free-breathing acquisition followed by a rigid-images registration. A 5-parameters dual input one compartment model was used to estimate quantitative perfusion parameters. Sixteen patients with chronic liver diseases were prospectively enrolled. Hepatic Perfusion Index and portal blood flow were found relevant parameters to discriminate between F2, F3 and F4 METAVIR stages (p<0.03). Mean transit time and total blood flow between F2, F3 and F4 stages were significantly different (p<0.05). Arterial blood flow allowed only to separate F2, F3, F4 with F0 and F1 stages (p<0.03). High molecular weight of MS-325 complex appears well suited to evaluate liver fibrosis.

                  2595.     Safety of Gadobenate Dimeglumine and Other Gadolinium Contrast Agents in Intraindividual Crossover Studies

Matthew J. Kuhn1, Howard A. Rowley2, Cesare Colosimo3, Michael V. knopp4, Kenneth R. Maravilla5, Zoran Rumboldt6

1Radiology, University of Illinois at Peoria, Peoria, IL, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Radiology, University of the Sacred Heart, Rome, Italy; 4Radiology, Ohio State University, Columbus, OH, United States; 5Radiology and Surgery, University of Washington, Seattle, WA, United States; 6Radiology, Medical University of South Carolina, Charleston, SC, United States

Safety results from 5 prospective, randomized, intraindividual crossover comparison studies of gadobenate dimeglumine with other gadolinium agents for magnetic resonance imaging (MRI) of the central nervous system (CNS) are reviewed. The overall rate of adverse events in these studies was 6.0%. The type and rate of adverse events was similar after gadobenate dimeglumine and the comparator agents with no significant differences noted between agents in any study.

                  2596.     The Hepatic Uptake of Gd-EOB-DTPA Is Strongly Correlated with the Uptake of Gd-BOPTA

Olof Dahlqvist Leinhard1,2, Nils Dahlström1,2, Per Sandström3, Johan Kihlberg4, Torkel Brismar5, Örjan Smedby1,2, Peter Lundberg, 2,6

1Faculty of Health Sciences/IMH, Linköping University, Linköping, Sweden; 2Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; 3Dep. of Surgery, Linköping University Hospital; 4Radiology, Linköping University Hospital; 5Karolinska University Hospital, Stockholm, Sweden; 6Radiation Physics, Linköping University Hospital

In this study quantitative measurements of the hepatic uptake of the liver-specific contrast agents Gd-EOB-DTPA and Gd-BOPTA were analyzed using a simple pharmacokinetic model in a group of 10 healthy subjects. A significant correlation was found in a pairwise comparison of the uptake of the two contrast agents.

                  2597.     Dynamic Contrast-Enhanced MRI in the Liver at 3T with Dual-Input Pharmacokinetic Model Analysis

Andrew Brian Gill1, Lorenzo Mannelli1, Peter Beddy1, Richard T. Black1, Ilse Joubert1, Andrew N. Priest1, Martin J. Graves1, David J. Lomas1

1Dept of Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

This study reports hepatic perfusion measurements made with DCE-MRI at 3T, performed so as to allow analysis using a dual-input kinetic model which separates perfusion components from the hepatic artery and portal vein. DCE data acquisition had a single-heartbeat time resolution and employed a dual saturation-recovery sequence to sample high [Gd] in the blood near-simultaneously with low [Gd] in the liver parenchyma. Mean results for total perfusion (69 ± 24 ml/min/100ml) and arterial fraction (16 ± 7 %) from 7 healthy volunteers were in line with those reported by other groups collecting data at 1.5T.

                  2598.     Non-Contrast-Enhanced Hepatic MR Arteriography with Two-Dimensional Parallel Imaging and Short Tau Inversion Recovery Methods to Shorten Acquisition Time Without Image Quality Deterioration

Hiroyoshi Isoda1, Kotaro Shimada, Tomohisa Okada, Shigeki Arizono, Toshiya Shibata, Kaori Togashi

1Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto, Japan

To study whether shortening of acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Shortening of the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

                  2599.     High Temporal Resolution 4D Contrast Enhanced Liver MR Imaging Using Spiral Trajectory and Sliding Window Reconstruction

Bo Xu1,2, Pascal Spincemaille2, Beatriu Reig2, Fei Sun3, Martin R. Prince2, Yi Wang, 2,3

1Department of Biomedical Engineering, Cornell University , Ithaca, NY, United States; 2Department of Radiology, Weill Cornell Medical College, New York, NY, United States; 3Department of Biomedical Engineering, Cornell University, Ithaca, NY, United States

In this work, high temporal resolution 4D dynamic contrast enhanced liver MR imaging is achieved using a stack of spirals trajectory and sliding window reconstruction in healthy volunteers. This allows the detection and characterization of liver lesions in the arterial and later phases without the need for accurate contrast bolus timing. Additionally, a retrospective selection of the optimal arterial phase is possible and the determination of hepatic artery anatomical variants can be done with increased diagnostic confidence.

                  2600.     Fat Fraction Measurement Using MFFE Sequence with T2* Correction and Little T1 Dependence: Experience in Chronic Liver Disease Patients Before and After Gd-EOB-DTPA Enhancement

Kengo Yoshimitsu1, Tomoyuki Okuaki2, Shutaro Saiki2, Marc van Cauteren2

1Radiology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan; 2Philips Medical Systems, Tokyo, Japan

Newly developed mFFE can provide consistent fat fraction regardless of T2* or T1 alteration of the liver tissue as compared to conventional dFFE, and therefore is particularly useful in evaluation of steatosis in chronic hepatitis C or non-alcoholic steatohepatitis patients, in whom considerable amount of iron may also acculmulate in the liver.

                  2601.     SWI-Based Method for Emphasizing Susceptivity Changes on Liver T2* Multi-Echo Gradient-Echo MRI

Maria Filomena Santarelli1,2, Nicola Martini2, Vincenzo Positano, 12, Alessia Pepe2, Daniele De Marchi2, Luigi Landini, 1,3, Massimo Lombardi2

1Institute of Clinical Physiology, National Research Council (CNR), Pisa, Italy; 2Tuscany Foundation "G. Monasterio", Pisa, Italy; 3Information Engineering, EIT, University of Pisa, Pisa, Italy

A method is suggested, based on a SWI approach, that increases the contrast between tissues of different susceptivity, in liver T2* multi-echo gradient-echo images.

                  2602.     Assessment of Liver Iron Overload by Combining Fast T1-Mapping and T2*-Mapping

Christian Kremser1, Benjamin Henninger1, Stefan Rauch1, Heinz Zoller2, Wolfgang Vogel2, Werner Jaschke1, Michael Schocke1

1Dept. of Radiology, Innsbruck Medical University, Innsbruck, Tyrol, Austria; 2Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Tyrol, Austria

The assessment of liver iron overload by means of magnetic resonance imaging is usually based on the quantification of T2* values. It was the purpose of this study to investigate if a combination of T2* values and T1 values, obtained with a fast T1 mapping technique, could be beneficial for diagnosis.

                  2603.     Whole Liver T1,T2, and T2* Relaxation Mapping Using Echo Planar Imaging

Caroline L. Hoad1, Alexander G. Gardener1, Ji-Young Lim1, Carolyn Costigan2, Robin C. Spiller3, Penny A. Gowland1, Luca Marciani3, Guru P. Aithal3, Susan T. Francis1

1School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom

T1, T2 and T2* relaxation maps of the whole liver of chronic liver disease patients were generated using respiratory triggered IR-SE-EPI, SE-EPI and GE-EPI datasets respectively.  These maps were used to generate voxel-by-voxel histograms of the liver tissue, the central peak data of the histogram being predominately from bulk tissue (excluding vessels).  This method of analysis provided a robust result, with minimal variation in the peak data when the shape of the mask was altered.  A significant spread in measured peak relaxation times is found in patients with chronic liver disease.

                  2604.     Measuring T2 in the Liver. a Comparison Between 1H Spectroscopy and SE-EPI

Caroline L. Hoad1, Mary Stephenson1, Ji-Young Lim1, Alexander G. Gardener1, Carolyn Costigan2, Robin C. Spiller3, Penny A. Gowland1, Luca Marciani3, Guru P. Aithal3, Susan T. Francis1

1School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom

Relaxation time T2 was measured in liver water tissue of 18 chronic liver disease patients using multiple TE MRS and SE-EPI T2 mapping.  There was good agreement between T2 measured using MRS and the mean T2 measured across the liver maps (including blood vessels), however peak (mode) T2 data from the EPI maps (bulk tissue only) consistently measured a shorter T2 compared to the MRS data, suggesting the MRS data ‘tissue’ T2 contained some components from blood.  There was considerable variation in T2 of the liver of patients with chronic liver disease possibly reflecting differences in iron content and liver fibrosis.

                  2605.     Fast 3D Dynamic Contrast-Enhanced MRI Pre- And Post-Secretin for Evaluating the Severity of Chronic Pancreatitis

Patrick Hawkins1, Numan C. Balci2, Sharon C. Forrest3, Frank Burton4, Samer Alkaade4, Thomas Perkins5, William H. Perman1

1Radiology, Saint Louis University School of Medicine, St. Louis, MO, United States; 2Radiology, Saint Louis University, St. Louis, MO, United States; 3Department of Radiology, Saint Louis University Hospital, St. Louis, MO, United States; 4Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, United States; 5Philips Healthcare, Cleveland, OH, United States

Currently, secretin stimulation is utilized in MRCP Cambridge classification of chronic pancreatitis.  Our study intends to correlate pre- and post-secretin pancreas perfusion with a more precise classification of chronic pancreatitis.  Fast 3D dynamic contrast-enhanced MR perfusion scans were performed on 12 subjects with suspected chronic pancreatitis using a 3D T1 weighted turbo field echo pulse sequence.  Comparison of the perfusion values between Cambridge type 3 and type 1 subjects, with normal exocrine function demonstrate a significant difference in regional and average arterial to tissue wash-in and wash-out rates.  Conclusion: Contrast-enhanced MRI shows promise as a staging technique for chronic pancreatitis.

                  2606.     Investigating Iron Deposition in Hepatic Diseases  Using Susceptibility Weighted Imaging - Initial Experiment

Yongming Dai1, Daoying Gen2, Jiani Hu3, E.M. Haacke3

1Siemens Ltd China, Healthcare, Magnetic Resonance Imaging, Shanghai, China; 2Fudan University affiliated Huashan Hospital, Shanghai, China; 3Wayne State University, United States

In this study, susceptibility weighted imaging has been extended from human brain to abdomen for iron deposition research of hepatic diseases. From the inital result, susceptibility weighted imaging could correlate the degree of hepatic iron overloaded of patients with their clinical examination results well. It seems that susceptibility weighted imaging will be a promising method alternative to conventional T2, T2star methods for iron deposition research.

                  2607.     T1_rho Dispersion MR Imaging for the Diagnosis and Characetrizaton of Different Liver Pathologies

Dania Daye1, Kejia Cai2, Mohammad Haris2, Anup Singh2, Santosh Gaddam2, Rebecca Wells3,4, Emma Furth, Ravinder Reddy2

1Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Medicine, University of Pennsylvania, Philadelphia, PA; 4Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States

It has been previously shown that T1ρ weighted MR imaging has significant potential to provide for a non-invasive assessment of liver disease, specifically in fibrosis. In T1ρ weighted imaging, nuclear spins are locked with a radiofrequency locking field, yielding a longitudinal relaxation time (T1ρ) in the rotating frame. By varying the strength of the locking field (B1), it is possible to make the T1ρ relaxation time changes sensitive to different contrast mechanisms in tissues. Here, we show that that T1 ρ dispersion technique has significant potential to differentiate between different liver pathologies as well al further characterize certain pathologies, such as fibrosis.

                  2608.     Quantitative Assessment of Iron Overload in Liver of  Patients with Thalassemia Major Using Ultra-Short T2*

azza abdelrahim ahmed1, Taigang He2, Dudley Pennell2, David Firmin2

1CMR, imperial college london, London, Kensignton and Chelsea, United Kingdom; 2Imperial college london

Attempts were made in measuring ultra-short T2*(<1ms) for accurate assessment of iron  in the liver of patients with thalassemia major. A new sequence was developed by minimizing duration of RF pulse and shortening the ramp times and duration of field gradients. The sequence tested in phantom involved an initial echo time was reduced to 0.8ms and echo spacing to 0.6ms. For liver imaging, an echo spacing of 1.9ms was used. The developed sequence was later compared with conventional one. Results show a feasibility of measuring ultra-short T2* values in phantoms and in liver of patients using the improved sequence.

                  2609.     Clinical Application for Cirrhosis with Susceptibility Weighted Imaging

Yongming Dai1, Daoying Gen2, Wei Cheng3, E.M. Haacke4

1Siemens Ltd China, Healthcare, Magnetic Resonance Imaging, Shanghai, China; 2Fudan University affiliated Huashan Hospital; 3The Third Military Medical University affiliated SouthWest hospital; 4Wayne State University, United States

In this study we extended clinical application for hepatic disease (Cirrhosis)with susceptibility weighted imaging (SWI). The results showed promising future for SWI application in human abdomen.

                  2610.     A Software Phantom Generator System for Quality Control (QA)  of  MRI Iron Overload Assessment Software

Bahman Kasmai1, Paul Napier Malcolm1, Andoni Paul Toms1, Andrew Brian Gill2

1Radiology, Norfolk & Norwich University Hospitals NHS Trust, Norwich, Norfolk, United Kingdom; 2Radiology, Papworth Hospital NHS Foundation Trust, Cambridge, Cambridgeshire

The aim of this work was to develop  a software tool for validation, evaluation and integrity checks of in-house and commercial MRI iron overload systems. A windows-based software application, called SOFGEN,  written in C# and based on Microsoft .NET framework generates  a sets of fully Dicom compliant images from a set of user supplied parameters and decay model,  for testing of Dicom compliant MRI T2(*) assessment software.  The SOFGEN generated phantoms were successfully used to evaluate a number of  in-house developed T2(*) assessment software and is available free via email request to authors. 

                  2611.     Effects of Posprandial State and Mesenteric Blood Flow on the Repeatability of Magnetic Resonance Elastography

Catherine D. G. Hines1, Mary J. Lindstrom2, Scott B. Reeder1,3

1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 2Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States

Blood flow and fasting status are recognized sources of variability in MRE measurements, and their impact on the repeatability of MRE is evaluated.  MRE stiffness values and flow through the superior mesenteric vein were measured in twelve healthy volunteers in fasted and fed states, and the sequences were repeated five weeks later. No significant differences between fasted/fed state stiffness values and no correlation between values and measured flow are seen.  Overall, volunteers scanned in a known fasted or fed state provide very repeatable MRE stiffness values, where the standard deviation of one MRE exam is 8.5% or 9.0% for fasted and fed states, respectively.

                  2612.     Three-Dimensional MRCP with Reduced RF Power Deposition

John P. Mugler, III1, Wilhelm Horger2, Berthold Kiefer2

1Radiology, University of Virginia, Charlottesville, VA, United States; 2Siemens Healthcare, Erlangen, Germany

This work explored two approaches for reducing the RF power deposition of MRCP imaging based on a turbo-spin-echo pulse sequence. An adiabatic T2 preparation applied just before the excitation RF pulse, or a very long first echo spacing, combined with partial-Fourier acquisition permitted power deposition to be reduced by 25%-40% compared to that for a standard MRCP pulse sequence, while providing image quality comparable to that for the standard method.  These methods will be valuable for addressing power-deposition limitations of MRCP at 3T, and will permit more consistent MRCP image quality to be achieved.

                  2613.     T2-Weighted Body Imaging with PROPELLER Using Parallel Imaging with Across Blade Calibration

James H. Holmes1, Philip J. Beatty2, Scott B. Reeder3,4, Zhiqiang Li5, Reed F. Busse1, Ajeetkumar Gaddipati6, Jean H. Brittain1

1Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 5GE Healthcare, Phoenix, AZ; 6GE Healthcare, Waukesha, WI, United States

This work demonstrates the application of a shared calibration scheme for autocalibrated parallel imaging to enable greater blade acceleration for abdominal PROPELLER. The shared calibration method uses external calibration data as well as a small amount of internal calibration data per blade. The technique is shown to improve robustness to motion for free-breathing T2-weighted abdominal body imaging. Results were found to compare favorably to respiratory-gated Cartesian exams suggesting that the PROPELLER approach may allow robust imaging in individuals where respiratory gating is not effective.

                  2614.     Balanced MR Cholangiopancreatography with Motion-Sensitized Driven-Equilibrium (MSDE): Feasibility and Optimization of Imaging Parameter

Tomohiro Nakayama1, Takashi Yoshiura1, Yukihisa Takayama1, Eiki Nagao1, Tsuyoshi Tajima1, Akihiro Nishie1, Yoshiki Asayama1, Kousei Ishigami1, Daisuke Kakihara1, Daisuke Okamoto1, Hiroshi Honda1, Tomoyuki Okuaki2

1Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; 2Philips Electronics Japan

Motion-sensitized driven-equilibrium (MSDE) preparation was added to a balanced SSFP MRCP sequence in order to suppress disturbing high signal intensities from flowing blood in vessels. We performed a volunteer study to determine optimal VENC value for the evaluation of biliary systems. We found the optimum VENC values to be 3 or 5cm/s with best suppression of relative vessel signals to bile ducts. At a lower VENC value (1cm/s), signal of bile duct was reduced likely due to minimal biliary flow.  Higher VENC values (> 7cm/s) resulted in failure of vessel signal suppression.

                  2615.     Respiratory Navigator-Triggered, Multi-Slice Turbo Spin Echo with Motion-Sensitized Driven Equilibrium Prepulse: A Novel Sequence for Black-Blood T2-Weighted Imaging of Liver

Gregory James Wilson1,2, George R. Oliveira2, Jeffrey Harold Maki, 2,3

1MR Clinical Science, Philips Healthcare, Cleveland, OH, United States; 2Radiology, University of Washington, Seattle, WA, United States; 3Radiology, Puget Sound VA HCS, Seattle, WA, United States

Black-blood (BB) T2-weighted (T2w) imaging can provide increased liver lesion conspicuity over standard bright-blood T2w imaging. The sequence evaluated here uses respiratory navigator-triggering and a motion-sensitized driven equilibrium (MSDE) pre-pulse with a multi-slice turbo spin echo (TSE) readout. This sequence provides BB T2w images with high TSE image quality and without EPI distortions. In this study, various motion-sensitizing gradient directions and strengths were evaluated.

                  2616.     Single Breath-Hold High Spatial Resolution Abdominal  Imaging and T2* Mapping at 7.0 T

Matthias Alexander Dieringer1,2, Fabian Hezel1, Wolfgang Renz, 1,3, Philipp Boyé, 12, Bernd Ittermann, 1,4, Frank Seifert, 1,4, Tomasz Lindel, 1,4, Thoralf Niendorf1,2

1Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany; 2Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany

Abdominal imaging examinations constitute a growing fraction of clinical MRI exams. Since ultrahigh field magnetic resonance imaging becomes more widespread, a range of applications established in the clinical scenario at 1.5 T and 3.0 T is emerging at 7.0 T. An eight channel transceiver surface coil array together with a 2D fast gradient echo sequence delivered high details of abdominal sub-millimeter anatomic structures, such as the gallbladder wall and subtle liver vessels without the application of contrast agent, and enabled T2*-Mapping of the liver at 7.0 T.

                  2617.     MR Imaging of the Human Biliary Tree Using a Flexible Catheter-Mounted Radio-Frequency Detector Microcoil

Christopher Antony Wadsworth1, Shahid A. Khan1, Simon D. Taylor-Robinson1, Wladyslaw M W Gedroyc2, Munir M. Ahmad3, Richard R. A. Syms3, Ian R. Young3

1Department of Hepatology & Gastroenterology, Imperial College, London, United Kingdom; 2MRI Unit, Imperial College Healthcare NHS Trust, London, United Kingdom; 3Department of Electrical and Electronic Engineering, Imperial College, London, United Kingdom

Problem: Strictures in the biliary tree are difficult to characterise as benign or malignant. A RF receiver microcoil applied directly to the biliary tree should improve MRI resolution substantially. Method: An innovative flexible catheter mounted microcoil has been developed. This was used as the receiver coil in MR imaging of a resected liver and biliary tree. Results: High resolution images were obtained. Signal to noise ratios and resolution were substantially better with the microcoil than with the standard coil. Conclusion: A prototype RF microcoil receiver can produce high quality images of ex vivo human liver tissue. These images demonstrate interpretable anatomical detail with sub-millimetre resolution and are superior to those obtained using a standard body coil.

                  2618.     High Spatial and Temporal Resolution Perfusion Imaging of Hepatocellular Carcinoma with Time-Resolved 3DPR Using a 32-Channel Coil at 3T

Ethan K. Brodsky1,2, Walter F. Block2,3, William Schelman4,5, Scott B. Reeder1,2

1Radiology, University of Wisconsin, Madison, WI, United States; 2Medical Physics, University of Wisconsin, Madison, WI, United States; 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States; 4Carbone Cancer Center, University of Wisconsin, Madison, WI, United States; 5Medicine, University of Wisconsin, Madison, WI, United States

Detection, characterization, and monitoring of hepatocellular carcinoma (HCC) is challenging due to its variable and rapid arterial enhancement. The ability to monitor changes in both morphology and perfusion is essential for evaluating the effectiveness of anti-angiogenic therapies. Multiple-phase CE-MRI has traditionally been used, but suffers from limited temporal resolution and an inability to consistently match acquisitions to the desired enhancement phase. We demonstrate the feasibility of contrast-enhanced isotropic-resolution 3DPR acquisition at 3T using a 32-channel coil with real-time monitoring that allows breath-holds to be matched to the desired enhancement phase and enables retrospective selection of the temporal window showing optimal lesion contrast.

                  2619.     Contrast Uptake Enhancement Patterns in Neuroendocrine Liver Metastases

Choon Hua Thng1, Tong San Koh2, Septian Hartono1, Puor Sherng Lee1, Keiko Miyazaki3, David Collins3, Martin O. Leach3, Val Lewington4, Dow-Mu Koh4

1National Cancer Centre Singapore, Singapore, Singapore; 2Nanyang Technological University, Singapore, Singapore; 3CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, United Kingdom; 4Royal Marsden NHS Foundation Trust, Sutton, United Kingdom

Neuroendocrine liver metastases have been described as being hypervascular in nature, showing arterial enhancement and washout. However, other enhancement patterns have been observed in clinical practice (plateau and progressive enhancement). Three types of enhancement curves in neuroendocrine tumor was found: (1) Rapid increasing followed by decrease, (2) Rapid increasing followed by plateau, and (3) Progressively increasing. Type I pattern show higher intravascular volume (v1) compared to percentage of interstitial volume (v2). Type II and III pattern show higher v2 compared to v1. Type I pattern show higher blood flow (F) compared to Type II/III.

                  2620.     Clinical Experience with Gadoxetate-Enhanced T1 Weighted Hepatobiliary Imaging in Primary Sclerosing Cholangitis

Andrzej Roman Jedynak1, Frederick Kelcz1, Alex Frydrychowicz1, Scott K. Nagle1,2, Scott B. Reeder1,3

1Radiology, University of Wisconsin, Madison, WI, United States; 2Radiology, Middleton Veterans Affairs (VA) Hospital, Madison, WI, United States; 3Medical Physics, University of Wisconsin, Madison, WI, United States

Primary sclerosing cholangitis (PSC) is a chronic inflammatory condition of extra- and intra-hepatic biliary ducts. In our clinical practice we routinely use the combination of high resolution gadoxetate-enhanced T1-MRC and heavily T2-weighted MRCP for the evaluation of PSC. This work set out to validate the clinical diagnostic utility of adding high-resolution 3D T1-weighted gadoxetate-enhanced hepatobiliary phase MRC to 3D T2 weighted MRCP. Preliminary results indicate that T1-MRC is an excellent adjunct to T2 MRCP that provides not only anatomical visualization of the biliary tree and associated disease but also offers useful functional/physiologic information that can be tremendously helpful in many cases.

                  2621.     Gd-EOB-DTPA as a Correlate for Chronic Liver Disease Through Contrast Uptake, Uptake Rate, and Bile Excretion

Hiroumi Kitajima1, Puneet Sharma, Christina Lurie, Khalil Salman, Gaye Ray, Bobby Kalb, Diego Martin

1Emory University, Atlanta, GA, United States

Gd-EOB-DTPA demonstrates liver clearance kinetics that allow for its use as a marker for patients with chronic liver disease.  Signal uptake, uptake rate, and common bile duct excretion as imaged by 3D T1-weighted GRE allow for quantitative assessment of liver fibrosis.

                  2622.     MR Cholangiopancreatography: Does Butylscopolamine (Buscopan®) Make a Difference to Ductal Visualization?

Natalie Yang1, Sarah Jenkins1, Errol Colak1, Anish Kirpalani1

1Radiology, St Michael's Hospital, Toronto, Ontario, Canada

The effect of butylscopolamine (Buscopan) on image quality for MR cholangiopancreatography (MRCP) examinations is examined in our study.  The inferior common bile duct demonstrated improved visualization after the administration of butylscopolamine whilst other ductal segments demonstrated minimal benefit.  The use of butylscopolamine in patients with suspected inferior common bile duct disease improves image quality and thus may improve diagnosis.

                  2623.     MRI of Intrabiliary Delivery of Motexafin Gadolinium Into Common Bile Duct Walls: In Vitro and Ex Vivo Evaluations

feng zhang1, Huidong Gu1, Yanfeng Meng1, Bensheng Qiu1, Xiaoming Yang1

1Image-Guided Bio-Molecular Intervention Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA, United States

MR imaging was used to investigate the capability of Motexafin gadolinium(MGd) entering human cholangiocarcinoma cells (Mz-ChA-1) and the feasibility of intrabiliary local delivery of MGd into the common bile duct(CBD) wall. T1 weighted MR imaging of Mz-ChA-1 cells treated with MGd demonstrated a linear increase of signal intensities(SI) from 25 to 75-¦Ìg/mL MGd,  and a plateau pattern of SIs from 75 to 150-¦Ìg/mL MGd. Confocal microscopy showed MGd internalized Mz-ChA-1 cells as intracytoplasm pink dots. Ex vivo experiments revealed significant higher contrast-to-noise ratio in the MGd-infused CBD walls than that in the controlled CBD walls with phosphate-buffered saline.

                  2624.     7T Liver MRI in Humans: Initial Results.

Lale Umutlu1, Andreas K. Bitz2, Stefan Maderwald3, Stephan Orzada3, Sonja Kinner4, Oliver Kraff, Irina Brote, Susanne C. Ladd, Gerald Antoch, Mark E. Ladd3, Harald H. Quick3, Thomas C. Lauenstein

1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen , Essen, Germany; 2Erwin L.Hahn Institute for Magnetic Resonance Imaging, Essen, Germany; 32Erwin L.Hahn Institute for Magnetic Resonance Imaging; 41Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen

Aim of this study was to investigate the feasibility of 7 Tesla liver MRI, with optimization and implementation of a dedicated examination protocol. 8 healthy subjects were examined at a 7T whole-body MR system utilizing a custom-built 8-channel RF transmit/receive body coil. Delineation of liver vessels, overall image quality and presence of artifacts was assessed. T1w imaging revealed very good delineation of liver vasculature, with best imaging scores for T1w 2D FLASH imaging. T2w TSE imaging remained strongly impaired by artifacts. This pilot study of dedicated hepatic imaging at 7 Tesla demonstrates the feasibility of in vivo ultra-high-field liver imaging.

                  2625.     In Vivo Evaluation of Exocytic Activity in Kupffer Cells Using Superparamagnetic Iron Oxide-Enhanced Magnetic Resonance Imaging; an Experimental Study on Gadolinium Chloride-Induced Liver Injury in Rats.

Toshihiro Furuta1,2, Masayuki Yamaguchi1, Ryutaro Nakagami1,3, Akira Hirayama1,4, Masaaki Akahane2, Manabu Minami5, Kuni Ohtomo2, Hirofumi Fujii1

1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan; 3Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 4GE Healthcare Japan, Hino, Tokyo, Japan; 5Tsukuba University Hospital, Tsukuba, Ibaraki, Japan

Hepatic signal recovery on MR images after a single dose of superparamagnetic iron oxide (SPIO) would be well correlated with exocytic activity of Kupffer cells (KCs). In this study, we actually showed the delay of hepatic signal recovery after SPIO administration depending on the severity of KCs' injury in an animal model, in which rat KCs were injured by intravenous administration of gadolinium chloride in a dose-dependent manner. We believe that at least two-week follow up MR imaging scans after SPIO administration are useful for the evaluation of not only phagocytic but also exocytic activities of KCs.

                  2626.     Qualitative and Quantitative Evaluation of Time-Resolved Flow Analysis of Portal Venous Hemodynamics of Liver Cirrhosis Patients and Volunteers

Zoran Stankovic1, Zoltan Csatari1, Peter Deibert2, Wulf Euringer1, Wolfgang Kreisel2, Susanne Eggerking2, Philipp Blanke1, Zahra Abdullah Zadeh1, Jürgen Hennig1, Mathias Langer1, Michael Markl1

1Department of Diagnostic Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany; 2Gastroenterology, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany

Time-resolved flow-sensitive 4D MRI permits qualitative and quantitative evaluation of portal venous hemodynamics of liver cirrhosis patients compared to volunteers. Our results demonstrate a persistent reduction of the peak velocities in the portal venous system between patients and different age group volunteers. Analysis showed significant correlation for peak and mean velocities between MRI and US measurements (r=0.53, p< 0.001) which served as reference standard. In liver cirrhosis patients 3D MR velocity mapping may be a standardized technique for evaluating flow characteristics modification, therapy monitoring or disease progression.

Metabolism, Diabetes & Spectroscopy

Hall B                        Tuesday 13:30-15:30                                                                                                 

                  2627.     Metabolic Profilings of Urine from High Fat-Fed Rats Based on 1H NMR Metabolomics

Jingjing Xu1, Changqin Liu2, Shuhui Cai1, Jiyang Dong1, Zhong Chen1

1Department of Physics, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China; 2The First Hospital of Xiamen Affiliated to the Xiamen University, China

The biochemical variations of urine from chow- and high fat-fed rats were investigated using NMR-based metabolomics. Two groups can be discriminated clearly according to the scores plot of partial least squares discriminant analysis. The plot of variable importance in projection shows that taurine, succinate, hippurate, choline, citrate, dimethylamine, acetate, dimethylglycine, creatine, creatinine, tyrosine, glycine and lactate are contributed to the classification. In addition, the metabolic change with the development of obesity was also explored.

                  2628.     Effects of a High-Fat Diet on Multiple Organ Systems in Mice: A MRI and MRS Study

Sabrina Doblas1, Philippe Garteiser1, Joanna DeMoe1, Tim Griffin1, Luke Szweda1, Rheal Towner1

1Oklahoma Medical Research Foundation, Oklahoma City, OK, United States

Magnetic resonance imaging is an in vivo imaging technique well adapted to measure and localize body fat contents and study obesity. Twenty-week old mice fed a high-fat or a normal diet were assessed on a 7 Tesla MRI system. Whole body, cardiac and knee joint images as well as cardiac 1H spectra were obtained and processed to assess the effects of a high-fat diet on adipose tissue distribution, joint damage and cardiac function. Fat mice had larger hearts, larger knee fat pads and fatter cardiac tissue than the lean animals.

                  2629.     An Animal Model for the Study of Developmental Origins of Adult Disease Associated to Dietary Fetal Fatty Acids: MRI Assessment

Kenneth Hollander1, Catherine Tempel-Brami2, Fred M. Konikoff1, Menahem Fainaru3, Alicia Leikin-Frenkel1

1Minerva Center for Lipid Metabolism in the Liver, Sackler School of Medicine, Tel Aviv University, Israel; 2Alfredo Federico Strauss Center for Computational Neuro-Imaging, Tel Aviv University, Tel Aviv, Israel; 3Department of Physiology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel

The mammalian fetus is completely dependent on the fatty acids supplied by its mother inside the uterus. In the present study we analyzed the impact of fatty acids in pregnant mother's isocaloric diet on obesity and insulin resistance in adult offspring (DOAD). Body fat in pregnant mothers and offspring was measured by MRI and correlated with tissues fat and insulin resistance in adult offspring. Essential Fatty Acids prevented adult offspring obesity and insulin resistance whereas saturated fatty acids promoted it. MRI measured body fat correlated with HOMA index, tissues lipid content and SCD activity in white adipose tissue.

                  2630.     AGAT-/- Mice: A Metabolic Puzzle of Energy Deficiency and Insulin Sensitivity

Patricia Maria Nunes1, Christine I. H. C. Nabuurs1, Dirk Isbrandt2, Cees Tack3, Arend Heerschap1

1Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Centre for Molecular Neurobiology, Institute for Signal Transduction, Hamburg, Germany; 3Department of General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands

Whole body creatine depletion causes several disarrangements in brain and muscle. In these conditions, AGAT-/-mice, a mouse model for deficient creatine biosynthesis, have enhanced food intake and permanent lower body weight which may reflect a higher substrate catabolism. We assessed ex vivo hepatic triglyceride concentration and the respective synthesis contributions from de novo lipogenesis (DNL) and dietary free fatty acids, by 1H /  2H-NMR. Additionally, we evaluated whole body glucose and insulin levels during a glucose tolerance test. Our results showed that AGAT-/- had lower hepatic triglycerides and the contribution from DNL, to this pool, was increased. On the contrary, dietary fatty acids contribute less to the hepatic triglyceride pool. This suggests that dietary fatty acids are preferentially recruited to high energy demanding tissues as muscle. These data matched with lower glucose and insulin concentrations during the glucose tolerance test, reflecting an insulin sensitive phenotype.

                  2631.     In Vivo High-Resolution Magic Angle Spinning Proton MR Spectroscopy of Drosophila Melanogaster Flies as a Model System to Investigate Obesity

Valeria Righi1,2, Yiorgos Apidianakis3, Dionyssios Mintzopoulos1,2, Loukas G. Astrakas, 1,4, Laurence G. Rahme3, A Aria Tzika1,2

1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States; 3Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 4Department of Medical Physics, University of Ioannina, Ioannina, Greece

We demonstrate biomarker profiles with high-resolution magic angle spinning proton MR spectroscopy (HRMAS H1 MRS) of live Drosophila melanogaster flies. We show that the metabolic HRMAS MRS profiles of adipokinetic hormone receptor (akhrnull) mutant flies, which have an obesity phenotype, are different from isogenic control strain flies (akhrrev). Our approach advances the development of novel, in vivo, non-destructive research approaches in Drosophila, suggests biomarkers for investigation of biomedical paradigms, and thus may contribute to novel therapeutic development in obesity.

                  2632.     Quantification of Adipose Tissue Depots in the Obese Thigh During Weight Loss Using Dixon Method

Curtis L. Johnson1, Mina C. Mojtahedi2, Diego Hernando3,4, Dimitrios C. Karampinos1,4, Matthew P. Thorpe2, Danchin Chen1, Ellen M. Evans2,5, John G. Georgiadis1,4

1Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 2Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 3Electrical and Computer Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 4Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 5Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States

MRI was used before and after a weight loss intervention investigating the effect of diet on body composition in obese, older women to quantify changes in adiposity in the thigh.  A two-point Dixon method was used to separate fat and water images in order to quantify subcutaneous, intermuscular, and intramuscular fat as well as muscle in the thigh before and after weight loss for two groups of subjects, one taking a protein supplement and the other taking a carbohydrate for control.  Results showed greater loss of adipose tissue and retention of muscle for the protein group compared to the control.

                  2633.     Magnetic Resonance Imaging of the Pancreatic Vasculature in Type 1 Diabetes

Zdravka Medarova1, Zeynep Onder1, Marytheresa Ifediba1, Dale Greiner2, Guangping Dai1, Gerrardo Castillo3, Elijah Bolotin3, Anna Moore1

1Molecular Imaging Lab, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States; 3PharmaIN, Ltd, Seattle, WA, United States

Vascular changes are commonly associated with many pathologies, including, cancer, arthritis, and diabetes. In type 1 diabetes, autoimmune lymphocytic infiltration progresses over many years, culminating in the destruction of a critical mass of insulin-producing beta-cells, and ultimately, in hyperglycemia and metabolic dysregulation. Vascular parameters, such as vascular volume, flow, and permeability are an important disease biomarker. It is important to monitor the dynamics of pancreatic microvasculature noninvasively. Here, we describe the application of the long-circulating, paramagnetic T1 contrast agent, PGC-GdDTPA-F for the noninvasive evaluation of vascular changes in a rat model of type 1 diabetes.

                  2634.     No Relation Between Altered Oxidative Mitochondrial Function and Impaired Muscle Perfusion in Type 2 Diabetes

Sandrine Duteil1,2, Sabrina Chiheb3, Claire Wary1,2, Emmanuel Cosson3, Aurélien Monnet1,2, Paul Elie Valensi3, Didier Mesengeau3, Pierre Georges Carlier1,4

1NMR Laboratory, Institute of Myology, F-75651 Paris, France; 2CEA, I²BM, MIRCen, IdM NMR Laboratory,, F-75651 Paris, France; 3Endocrinology, Jean Verdier Hospital, F- 93140 Bondy, France; 4CEA, I²BM, MIRCen, IdM NMR Laboratory, , F-75651 Paris, France

Microangiopathic complications are a major concern in diabetes mellitus type II. Oxidative phosphorylation may also be impaired, with a yet imprecise relationship to microangiopathy . An integrative investigation of metabolic and vascular response to stress was carried out to determine  possible alterations of perfusion and oxidative metabolism in calf muscle of 96 patients, categorized according to incidence of microangiopathy. Combining perfusion, oxygenation and energetic measurements, we could show that mitochondrial activity was altered in patients with poorly controlled glycaemia, but unrelated to reduced perfusion, which was common to all patients, while possible anomalies of oxygen diffusion might reflect diabetic microangiopathy.

                  2635.     Imaging Pancreatic Islets Ex Vivo by Ultra High Field of 14T, Combining Manganese and Iron-Oxide Enhanced MRI

Riikka J. Immonen1, Smaragda Lamprianou2, Laurent Vinet2, Paolo Meda2, Rolf Gruetter1,3

1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland; 2Department of Cell Physiology and Metabolism, University of Geneva, Geneva, CH-1210, Switzerland; 3Department of Radiology, University of Geneva and Lausanne, Geneva and Lausanne, CH-1210 and CH-1015, Switzerland

In diabetes the gradual loss of pancreatic β–cells leads to impaired regulation of blood glucose levels. β–cell islets, 30-600μm in diameter, are sparsely located accross the pancreas. We utilized for the first time ultra high field of 14.1T in combination of manganese- and iron-oxide nanoparticle-enhanced MRI to assess pancreatic structures ex vivo. We were able to distinguish all the main pancreatic structures, including lobules and branching duct tree with terminal acini. The manganese with glucose stimulus, without and together with the infusion of iron oxide particles, also delineated structures which are likely to correspond to individual pancreatic islets.

                  2636.     Could Obesity Possibly Be Harmless

Lidia S. Szczepaniak1, Jaime L. Legendre2, Edward W. Szczepaniak1, Angela L. Price2, Ildiko Lingvay2

1The Heart  Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States; 2Endocrinology, UT Southwestern Medical Center, Dallas, TX, United States

There is no doubt that obesity is associated with diabetes, increased cardiovascular risk factors, not to mention arthritis  and cancers. Sixty to 90% of patients with diabetes are obese but not all obese individuals present metabolic and cardiovascular diseases. This leads to a notion that certain individuals tolerate obesity well and without metabolic consequences. We present clinical evidence that given enough time the so called "healthy obesity" eventually becomes harmful with full spectrum of metabolic consequences.

                  2637.     Beneficial Effects of Diethylnorspermine in Obesity and Its Cardiac Complications

MingMing Li1, Beau Pontre2, Stephen Pickup3, Hong Xu4, Anthony Philips2, Garth Cooper2, Jun Lu2,5

1School of Biological Sciences, Auckland University, Auckland, New Zealand; 2School of Biological Sciences, Auckland University, New Zealand; 3Department of Radiology, University of Pennsylvania, Philadelphia, United States; 4College of Chemistry and Chemical Engineering, Shen Zhen University, Shenzhen, Guangdong, China; 5NCIECP, Auckland University of Technology, Auckland, New Zealand

We hypothesise that chemically induced Spermidine/spermine acetyl transferase (SSAT) activity, which stimulates polyamine catabolism and in turn enhances fat/glucose metabolism, would decrease fat content and improve cardiac function in obese mice. C57Bl/6 and matched leptin deficiency (ob/ob) mice were treated with a potent SSAT inducer, N1, N11-diethylnorspermine (DENS), through i.p. injection. Results showed that DNES not only can significantly reduce body fat percentages in both mice models, but also can control ob/ob’s body weight. Moreover, DENS can prevent the development of cardiac hypertrophy in obese mice. Therefore, SSAT is a potential target for the development of pharmacotherapy in obesity.

                  2638.     Patient Specific T2 correction in Hepatic Fat Content Measurement in Obese Patients

Annie M. Tang1, Kelvin K. Wong1, Kathleen Wyne2,3, Dikoma C. Shungu4, Willa Hsueh2,5, Stephen T. Wong1

1Center for Bioengineering and Informatics and Department of Radiology, The Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, TX, United States; 2Diabetes Research Center, The Methodist Hospital Research Institute, Houston, TX, United States; 3Division of Diabetes, Obesity & Lipids, The Methodist Hospital, Weill Cornell Medical College, Houston, TX, United States; 4Department of Radiology, Weill Cornell Medical College, Cornell University, New York, NY, United States; 5Division of Diabetes, Obesity & Lipids , The Methodist Hospital, Weill Cornell Medical College, Houston, TX, United States

1H-MRS is used for quantifying liver fat content  in patients with NAFLD. T2 corrections of hepatic fat/water are usually done using T2 values obtained in literature. However, these  T2 values of depends a lot on the concentration of iron in the liver. In patients with NAFLD, different degree of iron concentration was observed depending on the patient sex and diabetes status. We are conducting an ongoing pilot trial to study the hepatic fat content in obese patients before and during diet/weight management.  The hepatic water and fat T2 relaxation values were measured and its effects in hepatic fat content measurements were explored.

                  2639.     Triglyceride Composition Measured by 1H MRS at Clinical Field Strengths

Gavin Hamilton1, Michael S. Middleton1, Takeshi Yokoo1, Mark Bydder1, Michael E. Schroeder1, Claude B. Sirlin1

1Department of Radiology, University of California, San Diego, San Diego, CA, United States

The multi-peak structure of the fat 1H MR spectrum allows the triglyceride composition in adipose tissue to be estimated non-invasively. We assess the ability of 1H MR spectroscopy to reproducibly provide information about triglyceride composition in adipose tissue in vivo at clinical field strengths.

                  2640.     In Vivo Repeatability of Liver Fat Measurement Using 1H MR Spectroscopy

Gavin Hamilton1, Michael S. Middleton1, Takeshi Yokoo1, Masoud Shiehmorteza1, Claude B. Sirlin1

1Department of Radiology, University of California, San Diego, San Diego, CA, United States

We examined the repeatability of the liver fat fraction given by MR Spectroscopy.  We measured the fat fraction at 3T in vivo by collecting five single average STEAM spectra at progressively longer of TEs of 10, 15, 20, 25 and 30 ms in a single breath-hold to generate T2 and T2-corrected peak areas. We repeated this measurement three times per subject and showed this method produced highly repeatable liver fat fraction and water T2 estimates.  This method did not produce a repeatable estimate of fat T2.

                  2641.     On the Evaluation of 31P MRS Human Liver Protocols.

Mikael F. Forsgren1, Olof Dahlqvist Leinhard2,3, Bengt Norén4, Stergios Kechagias, Fredrik H. Nyström, Örjan Smedby2,3, Peter Lundberg, 3,4

1Linköping University; 2Faculty of Health Sciences/IMH, Linköping University, Linköping, Sweden; 3Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; 4Radiology, Linköping University Hospital

In this study the effect of proton decoupling, nuclear overhauser enhancement and repetition time was investigated in 31P liver MRS at 1.5T. An optimal protocol was determined and validate on 13 healthy volunteers.

                  2642.     Reproducibility Evaluation of Liver Metabolite Parameters: 1H Decoupled - 31P MRSI of Normal Volunteers at 1.5T

Jing Qi1, Amita Shukla-Dave1, Jason Koutcher1, Mithat Gönen2, Yuman Fong3, Lawrence H. Schwartz4, Kristen L. Zakian5

1Medical Physics, Memorial Sloan-Kettering Cancer Center; 2Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center; 3Surgery, Memorial Sloan-Kettering Cancer Center; 4Radiology, Sloan-Kettering Cancer Center; 5Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States

In order to evaluate reproducibility of liver metabolites measured by 1H decoupled-31P MRSI technique, 13 normal subjects were investigated twice at 2 weeks interval. Concentration of PE, PC, PME, Pi, GPE, GPC, PDE and NTP were calculated. Inter- and intra- subject variations were analyzed. Inter- and intra-subject coefficient variation ranged from 11% to 25 % for all metabolite concentration. Intra-subject reproducibility was not superior to inter-subject reproducibility, indicating that the random biological differences don’t seem to exceed the differences generated by technical variation in normal volunteers. Both technical and biological factors should be considered when interpret liver 31P MRSI data.

                  2643.     Comparison of Two Strategies to Improve Quality of in Vivo 1H MR Spectra in the Presence of Motion

Michael Germuska1, Jian Xu2, Martin Leach1, Geoffrey Payne1

1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, London, United Kingdom; 2Siemens Healthcare U.S., New York, NY, United States

In vivo 1H MR spectroscopy has proved valuable for evaluating tumours. However, acquisition of spectra in the abdomen is complicated by respiratory motion. The motion degrades the spectral quality by phase and frequency distortions and  by modification of the PSF. We compared two approaches to combat motion in liver spectroscopy. The first utilises a post-processing approach to correct phase and frequency distortions, the second employs prospective gating when acquiring the data. Both techniques showed an improvement in linewidth and SNR compared to free-breathing acquisitions. The post-processing methodology showed an advantage in SNR due to the increased number of signal averages.

                  2644.     Ω-3 Fatty Acid Detection by L-COSY in Human Bone Marrow at 3T

Saadallah Ramadan1, Robert V. Mulkern2, Carolyn E. Mountford1

1Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Radiology, Children’s Hospital, Boston, MA, United States

3 is an essential fatty acid (FA) that cannot be synthesized in the body and is obtained by diet. In the human body, essential FA serve multiple functions including neuroprotective functions, mood, behavior and prevents inflammation. There are two types of £s-3 FAs: eicosapentaenoic acid (EPA) docosahexaenoic acid (DHA), both  of these molecular structures end with R-HC=CH-CH2-CH3.  We investigated possibility of detecting  ƒç-3 in human bone marrow, at  3T,  using localised one dimensional (1D) (PRESS) and localized two-dimensional (2D) correlation spectroscopy (L-COSY).

Body Diffusion

Hall B                        Wednesday 13:30-15:30                                                                                                        

                  2645.     Effect of Region of Interest Position on Liver Apparent Diffusion Coefficient.

Daniel Wilson1, J. Ashley Guthrie2, Janice Ward2

1Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom; 2Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom

The liver ADC was measured in 3 different positions in the liver in 33 subjects. The mean ADC was signficantly different between the 3 different positions. This is attributed to the presence of noise in the middle of the liver and artefactual signal loss at high b-values at superior positions in the left lobe. Care must be taken when measuring ADC in the liver.

                  2646.     Continuously Moving Table Whole-Body MRI Using Variable Field of View

Robert L. Janiczek1,2, Jonathan W. Howard2, Giulio Gambarota2, John S. Thornton1, Xavier Golay1, Rexford D. Newbould2

1Institute of Neurology, University College London, London, United Kingdom; 2GSK Clinical Imaging Centre, London, United Kingdom

Continuously moving table (CMT) acquisitions have been proposed whereby data are collected in a hybrid space as the patient moves through the scanner. In CMT acquisitions the table velocity and therefore scan duration is proportional to the in-plane FOV. This work investigates the use of varying the FOV as a function of patient position in order to reduce scan time. A low-resolution scout scan is used to design a k-space sampling pattern that matches the minimal FOV requirement. The use of a variable FOV CMT acquisition is shown to reduce scan time by 32% over a conventional constant FOV design.

                  2647.     Diffusion-Weighted Imaging of the Abdomen with Readout-Segmented (RS)-EPI

Samantha J. Holdsworth1, Stefan Skare1, Shreyas S. Vasanawala1, Roland Bammer1

1Radiology, Stanford University, Palo Alto, CA, United States

Diffusion-weighted imaging (DWI) in the abdomen has proven useful for the various pathologies including liver lesion characterization and diagnosis of diffuse renal disease. However, image distortions arising from the use of EPI has shown to be problematic. In this work we explore the use of readout-segmented (RS)-EPI for DWI of the abdomen and show that it may be a useful method for reducing geometric distortion and blurring.

                  2648.     A Novel Whole Body Diffusion Weighted Imaging Technique with Continuously Moving Table: Preliminary Results

Yeji Han1, Sandra Huff1, Juergen Hennig1, Ute Ludwig1

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

Superior disease contrast and no need for extra administration of exogenous contrast medium contribute to the advantages of diffusion-weighted imaging (DWI) over other modalities for patient screening and treatment monitoring. However, the clinical impact of whole-body DWI (wbDWI) remains limited due to the technical difficulties of multistation approach. In this study, we have developed a continuously moving table (CMT) wbDWI method based on a STIR-EPI sequence as an alternative to currently used multistation wbDWI sequence. The preliminary results successfully demonstrate that CMT wbDWI can be a promising technique to overcome the problems of multistation wbDWI approach.

                  2649.     Characterization of Multicompartmental Renal Diffusion Using a Stretched Exponential Model

Claudia Lenz1, Gregor Sommer2, Klaus Scheffler1, Leopold Winter2, Markus Klarhöfer1

1Radiological Physics, University of Basel Hospital, Basel, Switzerland; 2Department of Radiology, University of Basel Hospital, Basel, Switzerland

In biologic tissues, microscopic motion of water not only includes molecular diffusion, but also microcirculation of blood in the capillary network. The intraxovel incoherent motion model has been introduced to describe these combined diffusion and microcirculation effects in diffusion weighted imaging. Analysis of the multicompartmental water diffusion is mostly performed by applying a biexponential fit function to the diffusion curve and evaluating the diffusion and perfusion components separately. However, this technique often suffers from high standard fit errors, especially for the perfusion fraction f. In 2003, Bennett et al. proposed a stretched exponential model to account for the multiexponential behavior of diffusion curves in the brain. In this work, we extended the stretched exponential model to the abdomen and present fit results from the kidneys of healthy subjects.

                  2650.     Interference of Inversion Recovery with Diffusion Weighted Imaging: Negative Apparent Diffusion Coefficients!

Thomas Gaass1, Bram Stieltjes, Frederik Laun1

1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany

The aim of this work was to evaluate whether diffusion weighted imaging (DWI) and inversion recovery (IR) may be applied without interference. DWI of the liver shows that the apparent diffusion coefficient (ADC) measured in a single voxel is clearly dependent on the inversion time and ADCs vary between -0.007 s/mm² and 0.009 s/mm² in a 100 ms TI interval. The counterintuitive negative diffusion is observed in the liver and in regions with incomplete fat saturation. This can be explained by the here proposed two compartment model. Thus, DWI and IR can generally not be applied without interference.

                  2651.     Diffusion-Weighted Imaging of the Kidney: Beyond Mono- And Bi-Exponential Models

Anna Caroli1, Luca Antiga1, Giuseppe Petralia2, Massimo Bellomi2, Andrea Remuzzi1,3, Paul Summers2

1Bioengineering Department, Mario Negri Institute for Pharmacological Research, Bergamo, Italy; 2Division of Radiology, European Institute of Oncology, Milan, Italy; 3University of Bergamo, Bergamo, Italy

Mono-exponential models do not accurately predict diffusion-weighted signal decay in the kidney, while bi-exponential models are unable to differentiate contributions. We propose a “piece-wise” exponential model, separately fitting low and high b-values with two exponentials, expressive of fast and slow transport components. Ten healthy volunteers underwent DWI both pre- and post-lunch, and acquisitions were repeated within one of the two sessions. The model was stable, and accurately fit signal attenuation. Diffusion parameters showed high repeatability, but significant differences between pre- and post-meal acquisitions. These results point out the need for more complete interpretations of DWI signal in describing the complex transport in the kidney.

                  2652.     Impact of Low and High B-Value MR Diffusion in HIV/HCV-Coinfected, HIV-Monoinfected and Uninfected Subjects

Susan Moyher Noworolski1,2, Phyllis Tien3,4, Michelle Nystrom1, Suchandrima Banerjee5, Aliya Qayyum1

1Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2The Graduate Group in Bioengineering, University of California, San Francisco and Berkeley, CA, United States; 3Medicine, University of California, San Francisco, CA, United States; 4Medicine, Veteran Affairs Medical Center, San Francisco, CA, United States; 5MR Applied Science Lab, GE Healthcare, Menlo Park, CA, United States

The impact of a perfusion regime, low b-value ADC, and a tissue regime, high b-value ADC were evaluated in comparison to a conventional ADC in three groups of subjects: HIV/HCV (hepatitis C) coinfection, HIV-monoinfection, and without infection. Liver ADC was measured using b values of 0 and 150 (ADClow), 150 and 600 (ADChigh) and 0 and 600 (ADCconv) in one breathhold sequence. ADClow and ADChigh provided unique information. HIV tended to have the highest ADC levels and was significantly higher than HIV/HCV for ADClow and ADCconv. HIV status may thus be an important consideration in interpretation of liver ADC.

                  2653.     SSFP Diffusion Prepared SSFSE

Weiying Dai1, Philip M. Robson1, David C. Alsop1

1Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

SSFP diffusion weighted imaging in the body can have improved image quality relative to echoplanar imaging. Its stronger diffusion attenuation of longer T2 fluid may also be a particular benefit in cancer screening studies, but the slow acquisition speed is a major limitation. Here we propose performing a diffusion weighted SSFP sequence as a preparation for a faster SSFSE sequence. The theoretical signal is described and pulse parameters are optimized. The resulting sequence is then applied to in-vivo diffusion weighted imaging of volunteers. Excellent suppression of fluid and blood signal is demonstrated.

                  2654.     Monitoring Random Molecular Diffusion and Tissue Perfusion in Rat Liver by Diffusion Weighted Proton MRI

Beena George1, Andriy Babsky1, Navin Bansal1

1Radiology, Indiana University, Indianapolis, IN, United States

Diffusion weighted (DW) 1H MRI may be useful in the diagnosis of liver diseases. Fast and slow apparent diffusion coefficients (ADCfast and ADCslow, respectively) were separated in the normal rat liver by using ten b values. After mortal ischemia, ADCfast disappeared, demonstrating that this component results from microcapillary blood perfusion. ADCslow decreased after ischemia, most likely due to intracellular accumulation of water.  DW 1H MRI can provide information about tissue perfusion and molecular diffusion which are both important physiological parameters.

                  2655.     Improved Robustness with a Stretched Exponential Model for Intravoxel Incoherent Motion (IVIM) DW Signal

Yousef Mazaheri1, Daniel B. Rowe2, Jingbo Zhang3, Hedvig Hricak3, Jason A. Koutcher1

1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States; 2Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI, United States; 3Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States

A stretched exponential model is presented to describe intravoxel incoherent motion (IVIM) signal. Simulations results show that the distributed diffusion coefficient and á is a dimensionless “stretching” parameter have tolerable CV (<15% at 5% noise) and bias (absolute bias< 11% at 5% noise).  In vivo renal data suggests that the stretched exponential model has potential to describe the pseudo-diffusion behavior at low b-values.

                  2656.     Relaxation Time Effects in Intra Voxel Incoherent Motion Imaging

Andreas Lemke1, Frederik Bernd Laun2, Dirk Simon3, Bram Stieltjes4, Lothar Rudi Schad1

1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 3Software Development for Integrated Diagnostics and Therapy, German Cancer Research Center, Heidelberg; 4Department of Radiology, German Cancer Research Center, Heidelberg, Germany

The DWI signal was measured as a function of the b-value in the pancreas using three different echo times (TE=50, 70, 100 ms) from six healthy volunteers. A modified equation incorporating relaxation effects was introduced and parameters derived from this equation were compared to the original IVIM equation. The perfusion fraction f increased significantly with increasing echo time (P=0.0025) whereas the relaxation time compensated perfusion fraction f' showed no significant dependence on TE (P=0.31). The relaxation time compensation had no influence on the diffusion coefficients.

                  2657.     Whole Body Diffusion Weighted Imaging for Distant Staging in Colorectal Cancer – Feasibility and Future Challenges

Doenja Lambregts1, Monique Maas1, Vincent Cappendijk1, Jan Verwoerd2, Iris Rutten1, Geerard Beets3, Regina Beets-Tan1

1Radiology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 2Philips Healthcare, Eindhoven, Netherlands; 3Surgery, Maastricht University Medical Center, Maastricht, Limburg, Netherlands

Whole-body diffusion weighted imaging (WB-DWI) could prove to be a promising and feasible alternative to CT and PET-CT for distant metastases screening in colorectal cancer. This study aims to test the feasibility of WB-DWI for metastases screening and to compare the lesion detectability of WB-DWI to conventional staging techniques (CT and PET-CT)

                  2658.     Liver Diffusion/perfusion Using Biexponential Analysis with 30 B-Values

James Lee1, Masoud Shiehmorteza1, Michael E. Schroeder1, Katie H. Hansen1, Mark Bydder1, Claude Sirlin1

1Radiology, University of California San Diego, San Diego, CA, United States

Diffusion imaging of the liver is reported as having slow and fast components ("perfusion"). We modeled both components before and after a meal to observe the effect of increasing perfusion.

Bowel/Fetal & Female Pelvis/Renal & Male Pelvis

Hall B                        Thursday 13:30-15:30                                                                                                           

                  2659.     MRI and MRS Monitoring of Gastrointestinal Distribution, Physiological Effects and Absorption of Fat Emulsions

Mahamoud Omar Hussein1, Luca Marciani2, Mary Stephenson1, Caroline L. Hoad1, Eleanor F. Cox1, Elisa Placidi1, Susan Pritchard1, Henelyta Ribeiro3, Elisabetta Ciampi3, Pip Rayment3, Asish Nandi3, Nick Hedges3, Paul Sanderson3, Irmela Kruse3, Robin C. Spiller2, Penny A. Gowland1

1The Sir Peter Mansfied Magnetic Resonance Centre, School of Physics & Astronomy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom; 2Nottingham Digestive Diseases Centre NIHR Biomedical Research Unit, The University of Nottingham, Nottingham, United Kingdom; 3Unilever Discover, Colworth Science Park, Bedford, United Kingdom

MRI can monitor gastrointestinal function and visualise the water and fat components of food in the gut separately. This study describes development work aimed to combine MRI and MRS to provide a method of monitoring the gastrointestinal fate and absorption of fat in the skeletal muscle and liver. Two healthy volunteers were fed two fat emulsions of different droplet sizes and were scanned at intervals postprandially. The 2 different meals triggered a diverse duodenal response affecting gastric emptying, gallbladder contraction and small bowel secretion. MRS showed promise for monitoring changes in both liver and calf lipid/water ratios.

                  2660.     Validation of Automated Motion Assesment in the Abdomen

Andre M. Sprengers1, Aart J. Nederveen2, Rolf M. Lamerichs3, Jaap Stoker2

1Radiology, AMC , Amsterdam, Netherlands; 2Radiology, AMC, Amsterdam, Netherlands; 3Research, Philips, Eindhoven, Netherlands

The assessment of small bowel motility is a difficult task because of its complex nature. SPAMM or SPatial Modulation of the Magnetization is a strong candidate for a minimally invasive, observer independent method of motion assessment. The SPAMM method uses a prepulse to impose a lineshaped pattern on the magnetization. Upon readout, this pattern is distorted as a result of tissue motion between prepulse and readout. Originally developed for cardiac imaging, the SPAMM sequence was reconfigured for nonperiodic motion.  The novel SPAMM technique was validated  by focussing on the heartmotion, breathing motion and small bowel motility.

                  2661.     Ultrafast Abdominal MR Imaging in Children and Young Adults with Multitransmit MR

Alisa Johnson1, Janusz Kikut1, Trevor Andrews2, Christopher G. Filippi3

1Radiology, Fletcher Allen Health Care-UVM, Burlington, VT, United States; 2MR, Philips Healthcare, Cleveland, OH, United States; 3Radiology, University of Vermont School of Medicine-Fletcher Allen Health Care, Burlington, VT, United States

The purpose of this study was to compare ultrafast imaging of the abdomen using multitransmit MR with routine, fast MR imaging in children and young adults who presented with acute abdominal pain to the emergency room.

10 patients were studied. 5 were normal, and in the other 5 patients, correct diagnoses were made. Multitransmit MR imaging quality was rated the same or better in all cases.  Improvements were noted in contrast, uniformity of fluid and fat signal, and less dielectric shading.  Scan times were reduced, on average, by 48%.  No sedation and no oral or intravenous contrast were needed. 

                  2662.     In Vivo Trans-Pyloric Mass Movement Dynamics Measured by Means of Phase-Contrast MRI

Tobias Hahn1, Jelena Curcic1, Martin Buehrer1, Oliver Goetze2, Werner Schwizer2, Michael Fried2, Andreas Steingoetter, 1,3, Sebastian Kozerke1, Peter Boesiger1

1Institute for Biomedical Engineering, ETH and University Zurich, Zurich, Switzerland; 2Division of Gastroenterology and Hepatology, University Hospital of Zurich, Zurich, Switzerland; 3Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany

This study aimed for assessing the feasibility of in vivo trans-pyloric flow measurements by means of phase-contrast MRI. Dynamic EPI sequences were studied in vitro and applied in vivo behind the pylorus. The gained velocity, frequency and backflow percentage show very good agreement with literature values and give rise for expecting great potential in fast EPI phase-contrast MRI for dynamic quantification of trans-pyloric mass movements.

                  2663.     The Impact of Abdominal Mri of Pregnant Women on Clinical and Obstetrical Management

Michal Marianne Amitai1, Miriam stern2, Marjory Hertz3, Yacov Itzchak3, yael Inbar3, Sara Apter3

1Diagnostic Imaging, Sheba Medical  Center, Ramat Gan, Israel, Israel; 2Diagnostic Imaging, Sheba Medical Center,, Ramat Gan, Israel,, Israel; 3Diagnostic Imaging, Sheba Medical Center, Ramat Gan, Israel, Israel

Purpose: To evaluate the impact of MRI of the abdomen and pelvis in pregnant women on clinical and obstetrical management. Methods: Thirty one consecutive MRI studies of the abdomen of 29 pregnant patients, were included in the study  Correlation between the MRI pathological findings related to the stage of pregnancy and the clinical and obstetric outcome were evaluated. Results: The indications for studies included: gynecologic conditions (9), suspected Crohn disease (7), suspected appendicitis (6), cancer staging and follow up (5), postoperative complications (3) and suspected pheochromocytoma (1). Conclusions: MR imaging proved to be appropriate in the management of pregnant patients with diverse abdominal pathology and could provide an accurate diagnosis prior to delivery in all patients.

                  2664.     The Effect of Maternal Smoking on Fetal Lung and Kidney Growth

Devasuda Anblagan1, Carolyn Costigan2, Tomas Paus2, Zdenka Pausova2, Nia Wyn Jones3, George Bugg3, Nick Raine Fenning4, Penny Anne Gowland1

1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, United Kingdom; 3Queen's Medical Centre, University of Nottingham, United Kingdom; 4Division of Human Development, School of Clinical Sciences, University of Nottingham, United Kingdom

This study aims to identify the effect of maternal smoking during pregnancy on fetal lung and kidney growth. Pregnant women were scanned at 24th to 26th weeks and 34 to 36 weeks postconception. The lung and kidney MR images were analysed using semi automatic approach with Analyze software. Fetal lung and kidney volumes were reduced in the smoker group.

                  2665.     Reliability Test for Fetal Fat Programme

Devasuda Anblagan1, Carolyn Costigan2, Alain Pitiot3, Tomas Paus2, Zdenka Pausova2, Nia Wyn Jones4, George Bugg4, Ruta Deshpande4, Mona S. Moghazy A. Salmam4, Penny Anne Gowland1

1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, United Kingdom; 3School of Psychology, University of Nottingham, United Kingdom; 4Queen's Medical Centre, University of Nottingham, United Kingdom

This study aims to investigate the reliability of a MATLAB program designed to calculate the subcutaneous fat volume in the fetus. It will be employed in a study investigating macrosomia outcomes in diabetic pregnant mothers. The MR technique used to assess the foetal growth is Fat Sequences with Water Suppression where pregnant women were scanned in late pregnancy (after 30th gestation week) when fetal fat is more visible.

                  2666.     Impact of Anti-Inflammatory Treatment on Placental and Neurodevelopmental Defects Monitored in Utero by MRI

Sylvie Girard1, Luc Tremblay2, Guillaume Sebire1, Martin Lepage2

1Pediatric, Universite de Sherbrooke, Sherbrooke, Qc, Canada; 2Radiobiology, Universite de Sherbrooke, Sherbrooke, Qc, Canada

Perinatal inflammation predominantly affects preterm newborns leading to brain damage. Interleukin-1 (pro-inflammatory molecule) appears to be a key mediator linking maternal inflammation and fetal brain damage. Strategies to protect the fetal brain are currently unavailable mainly due to the lack of non-invasive tools to detect in utero inflammation and monitor the impact of an anti-inflammatory treatment.  We showed that MRI is a potent technique to detect placental damage and can be used to monitor the impact of anti-inflammatory treatment in an animal model of prenatal inflammation.

                  2667.     Assessment of Placental Morphology and Magnetic Resonance Imaging Biomarkers at 1.5 Tesla

David M. Morris1,2, Caroline Wright3, Philip N. Baker4, Ian P. Crocker3, Penny A. Gowland5, Geoff J. Parker1,2, Colin P. Sibley3

1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Insitute, University of Manchester, Manchester, United Kingdom; 3Maternal & Fetal Health Research Centre, University of Manchester, Manchester, United Kingdom; 4Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada; 5Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom

Fetal growth retardation (FGR) is a serious condition affecting babies in utero that can be identified by means of a placental phenotype related to structural and functional changes in the placenta. Magnetic resonance imaging (MRI) measured the relaxation times T1 and T2 as possible biomarkers of this condition and placentas were collected for the histological verification of FGR pathology. We show for the first time that both in utero T1 and T2 demonstrate a significant negative correlation with the gestational age at 1.5 T and that relaxation times correlate with histological biomarkers of placental development.

                  2668.     T1-Weighted Imaging of Fetal Microcolon

Erika Rubesova1, James Gilmore1, Shreyas Vasanawala1, Richard A. Barth1

1Pediatric Radiology, Lucile Packard Children's Hospital at Stanford, Stanford, CA, United States

T1-weighted images allow visualisation of the fetal colon. Microcolon is important to recognize since it aids to accurate diagnosis in patients referred for fetal MRI with gastrointestinal abnormalities. In our retrospective study, we reviewed the T1-weighted images in fetuses with microcolon and tried to define the optimal plane andsequence (FGRE versus 3D dual-echo SPGR) for evaluation of the microcolon.

                  2669.     Using DCE-MRI to Determine Vascular Properties of Female Rhesus Macaque Reproductive Tissue: Pharmacokinetic Model Considerations

Ian J. Tagge1, Cecily V. Bishop2, Richard L. Stouffer2,3, Charles S. Springer, Jr. 1, Xin Li1

1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Division of Reproductive Sciences, ONPRC, Oregon Health & Science University; 3Department of Obstetrics and Gynecology, Oregon Health & Science University

The female uterus and ovary are among the few normal tissues to undergo periodic angiogenic changes.  Using a primate model (rhesus macaque), we investigate the feasibility of DCE-MRI to quantify blood volume fraction (vb) and contrast reagent (CR) transendothelial permeability.  The standard model with vb (SM2) and the second generation “shutter-speed” model (SSM2), are used in parallel for this effort.

                  2670.     Determining the Utility of Pre-Treatment MRI Data in Predicting the Survival Interval of Patients Diagnosed with Carcinoma of the Cervix Treated with Chemoradiotherapy

Martin D. Pickles1, Sue Booth2, Lindsay W. Turnbull1

1Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom; 2Institue of Oncology, St James' Hospital, Leeds, West Yorkshire, United Kingdom

Chemoradiotherapy in combination with brachytherapy has become the standard treatment for advanced cervical carcinomas. Although the intent of the treatment is curative a significant number of patients do not survive beyond 5 years.  Consequently, biomarkers of reduced survival intervals are currently being sought. The aim of this work was to determine if any of the studied MR derived parameters were associated with longer disease free and/or overall survival. This study demonstrated that for this cohort the MR derived stage (FIGO or TNM) based on morphological assessment of the disease present provided the most significant association with survival intervals.

                  2671.     Pelvic B1 Mapping at 3T for DCE

Rexford D. Newbould1, Brandon Whitcher1

1GSK Clinical Imaging Centre, London, United Kingdom

Dynamic contrast enhanced perfusion measurement (DCE) is hampered in the body at higher field strengths such as 3T by the large spread of achieved flipangles across the volume of interest.  In DCE, it is common to measure the change in voxel T1 using a variable flipangle spoiled gradient echo sequence, in order to quantify contrast agent concentration.  The extreme variation in achieved flip angle at 3T in the body has precluded accurate quantification.  Here, B1 mapping using the saturated double angle method is performed rapidly in the same locations as the dynamic scan, in order to correctly estimate T1 values.

                  2672.     MR Imaging in the Evaluation of (Deep) Infiltrating Endometriosis: The Value of Diffusion-Weighted Imaging

Milou Patricia Helene Busard1, Velja Mijatovic2, Cees van Kuijk, Indra Pieters-van den Bos, Peter Hompes, Jan Hein van Waesberghe

1Radiology, VUMC, Amsterdam, Noord Holland, Netherlands; 2Gynecology, VUMC, Amsterdam, Noord Holland, Netherlands

To assess the value of magnetic resonance (MR) diffusion-weighted imaging (DWI) in deep infiltrating endometriosis (DIE), DWI was added to the standard MR imaging protocol. Apparent diffusion coefficient (ADC) values were calculated using b-values of 50, 400, 800 and 1200 s/mm2. In 60 lesions, mean ADC values of DIE retrocervical (0.70 x 10-3/mm2 /s), infiltrating the colon (0.79 x 10-3/mm2/s) and bladder (0.76 x 10-3/mm2/s) were consistently low and did not significant differ between pelvic locations (p=0.63). In addition, ADC values show comparable diagnostic performance in differentiating endometrial cysts from other pelvic cysts as evaluation of T2- and T1-weighted images.

                  2673.     ASL, BOLD, and Phase Contrast MRI Measurements in the Kidneys of Normotensive and Hypotensive Swine.

David Joseph Niles1, Andrew L. Wentland1,2, Nathan S. Artz1, Thomas M. Grist1,2, Sean B. Fain1,2, Aji Djamali3, Elizabeth A. Sadowski2

1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 3Nephrology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States

Functional MR imaging techniques provide a non-invasive method for studying renal physiology. This study measured blood flow in the main renal artery using phase contrast MR, cortical and medullary perfusion using ASL and oxygenation using BOLD MR imaging sequences, in normotensive and hypotensive swine. Our results demonstrate medullary oxygenation is maintained despite a decrease in renal artery blood flow and regional tissue perfusion in the hypotensive states. This has been previously demonstrated by others with invasive probes in animals. Our functional renal MR techniques may be applied to future studies in humans to study blood flow and oxygenation simultaneously.

                  2674.     Diffusion-Weighted and Blood Oxygen Level-Dependent MRI in Renal Tubulointerstitial Nephropathy£ºInitial Experience

Xuedong Yang1, Ju Cao2, Xiaoying Wang1

1Department of Radiology, Peking University First Hospital, Beijing, China; 2Nephrology Department, Peking University First Hospital, Beijing, China

DW and BOLD MRI can reflect changes of water diffusion and oxygen level in TIN kidney. Both methods can be used to study the TIN patients. Combined use of the two methods may aid in differentiating ATIN, CTIN from normal kidney. Medullary R2* significantly correlates with eGFR in TIN patients.

                  2675.     Measurements of Renal Perfusion, Oxygenation, and Total Renal Blood Flow in Swine

Andrew L. Wentland1,2, Nathan S. Artz1, Arjang Djamali3, Thomas M. Grist1,2, Sean B. Fain1, Elizabeth A. Sadowski2

1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 3Nephrology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States

Given the recent link between nephrogenic systemic fibrosis and gadolinium-based contrast agents (GBCAs), it has become increasingly important to evaluate techniques that operate independently of GBCAs. In this study, measurements of perfusion, oxygenation, and total renal blood flow (TRBF) were acquired in swine with arterial spin labeling-based perfusion, BOLD MRI, and phase contrast MRI, respectively. Scans were repeated during a state of increased blood flow with acetylcholine and also a state of decreased blood flow with the anesthetic isoflurane over a two-hour period. Measurements successfully demonstrated increased perfusion, oxygenation, and TRBF with acetylcholine, and the opposite trend with isoflurane.

                  2676.     Renal-ASL Using a Multiple-Inversion Time, Free Breathing, STAR-HASTE Technique at 3T

Mark Stephen Dobbs1,2, Neil Woodhouse3, Geoff J.M Parker1,2, Josephine H. Naish1,2

1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, Greater Manchester, United Kingdom; 3AstraZeneca, Manchester, Greater Manchester, United Kingdom

ASL has been applied extensively in the brain, but there has been increasing interest in applying ASL to the kidneys, particularly as a result of concerns over the link between contrast agents and NSF. Currently, most human renal-ASL has been performed using a single inversion time, and applying a simple model for quantification. In this abstract we aim to demonstrate the feasibility of applying the Buxton model, at 3T, using a STAR based labelling technique and a free breathing approach. Here, we demonstrate the practicality of fitting for arrival time, producing high quality parametric output.

                  2677.     Non-Invasive Investigation of Diabetic Kidney Disease by Magnetic Resonance Imaging

Peter Edward Thelwall1, Roy Taylor1, Sally M. Marshall2

1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom; 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom

We have applied MR imaging methods to diabetic kidney disease by investigating the differences in kidney structure, blood flow and oxygenation between volunteers with Type 1 diabetes with and without diabetic nephropathy, and in non-diabetic control subjects. We hypothesised that early changes in kidney structure and function caused by diabetic nephropathy could be identified by altered renal structure, blood flow, and changes in oxygenation on water loading. Differences in renal artery flux were observed between volunteer groups.

                  2678.     Renal Perfusion Imaging with FAIR and FIESTA at 3.0T MR

Jing Wang1, Dongdong Liu2, Xuedong Yang3, Yi Dang1, Xiaoying Wang, 1,3, Jue Zhang1,2, Jing Fang1,2

1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 2College of Engineering, Peking University, Beijing, China; 3Dept.of Radiology, Peking University First Hospital, Beijing, China

Although Arterial Spin Labeling (ASL) being a non-invasive detection method has been used for many years, the respiratory and cardiac motions present major challenges when applying ASL. In this study, to measure the renal blood flow (RBF), a new abdominal ASL method was proposed by using single-shot fast imaging employing steady-state acquisition (FIESTA) combined with flow-sensitive alternation inversion recovery (FAIR) perfusion preparation on clinical 3.0T MR scanner. Results showed that the proposed technique had the ability to satisfy the renal perfusion quantification requirements, and the low renal perfusion area was also revealed clearly in a patient with an angioleiomyolipoma.

                  2679.     DCE-MRI of the Kidney Using BLADE – a Feasibility Study

Florian Lietzmann1, Frank G. Zöllner1, Henrik J. Michaely2, Stefan Haneder2, Ulrike Attenberger2, Lothar Rudi Schad1

1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany

Dynamic contrast enhanced MRI (DCE-MRI) provides a modern technique to assess physiological parameters like renal blood flow or glomerular filtration rate. The self-navigating BLADE-sequence with a certain robustness to motion artefacts in combination with an injection of a contrast agent offers an approach for a motion corrected DCE-examination without the need of respiratory triggering. The purpose of this study was to compare the T1-weighted BLADE sequence to the MR- gold standard TFL-sequence in clinical routine.

                  2680.     Assessing Kidney Perfusion Using Arterial Spin Labeling and Radial Acquisition for Rapid Characterization of Inflow Dynamics

Nathan S. Artz1, Kevin Johnson1, Yin Huang1, Elizabeth A. Sadowski2, Sean B. Fain1,2

1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Radiology, University of Wisconsin-Madison, Madison, WI, United States

Quantifying arterial spin labeling (ASL) perfusion measurements using data acquired at only one delay time requires assumptions for quantification that may be invalid, especially in diseased kidneys which may demonstrate a wide variety of blood flows.  The purpose of this study was to demonstrate the feasibility of efficiently acquiring data at multiple delay times using a radial balanced SSFP approach.  ASL-FAIR was performed in a healthy volunteer at 1.5 T during which unique radial projections were continually acquired from 0.2 to 2 seconds following inversion.  Twenty delay time images were acquired over 11 minutes.  The control and tag images show reasonable image clarity and the difference images clearly demonstrate perfusion however streaking is originating from below the left kidney (right side).  Future work will focus on reducing the streak artifact using motion compensation techniques and/or optimizing k-space trajectories.

                  2681.     A Prospective Study Following Patients with Chronic Kidney Disease Undergoing Contrast-Enhanced MRI

Matthew J. Kuhn1, Bryce K. Young1, N S. Mamillapalli2, Kalyani Vallurupalli3

1Radiology, University of Illinois at Peoria, Peoria, IL, United States; 2Radiology, Southern Illinois University, Springfield, Ilinois, United States; 3Radiology, Southern Illinois University, Springfield, IL, United States

As part of an ongoing prospective multicenter study to determine the incidence of NSF in patients with stages 3 to 5 chronic kidney disease (CKD) undergoing magnetic resonance imaging (MRI) of the central nervous system with gadobenate dimeglumine, 223 patients have been enrolled at 15 sites. Patients are followed for 2 years with a regular schedule of telephone calls and visits.  To date, no case of NSF has been reported, although follow-up is ongoing in most of these patients.

                  2682.     Low-Dose Contrast-Enhanced Time-Resolved Renal MRA

Hyun Jong Jeong1, James C. Carr2, Timothy J. Carroll1,2

1Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States

Dynamic imaging of the kidneys using MR offers non-invasive information about the renal anatomy and function.  However, despite many improvements in renal MRA, there is a need for higher temporal resolution in time-resolved MRA, while minimizing the risks associated with gadolinium based contrast agents.  In this study, low-dose renal MRA was performed using the previously developed CAMERA technique to achieve higher temporal resolution without undersampling.

                  2683.     PME Dynamics of  Pig's Kidney During Oxygenated Hypothermic Pulsatile (HPP) Compared to Cold Static Storage (CSS)

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

1Service of Radiology, University of Geneva and University Hospital of Geneva, Geneva, Switzerland; 2Center for Biomedical Imaging (CIBM), Lausanne and Geneva, Switzerland; 3Visceral and Transplantation Service, University of Geneva and University Hospital of Geneva, Geneva, Switzerland

In this study, we compare 2 cold storage conditions for transplantation using 31P CSI: Oxygenated pulsatile perfusion (O2+HPP) performed immediately after kidney harvesting vs. simple cold storage (CSS). We found that ATP did not fully recovered after 8 hours of CSS, and PME/Pi time constant was similar in both conditions (~0.05 h-1). Assessment of PME and ATP kinetics are important in the context of organ evaluation before transplantation as they may be considered as markers of kidney’s viability.

                  2684.     Measuring Glomerular Protein Leakage with Dual-Agent DCE-MRI: Reproducibility in Healthy Pigs

Mike Notohamiprodjo1, Michael Pedersen2, Klaus-Peter Lodemann3, Maximilian F. Reiser, Christian Glaser, Steven P. Sourbron

1Institute for Clinical Radiology, University Hospitals Munich, Munich, Bavaria, Germany; 2Skejby Sygehus Aarhus, Aarhus, Denmark; 3BRACCO S.p.a.

In this study a method is proposed to detect albumin leakage across the glomerular membrane with DCE-MRI. Four healthy piglets were examined with a dual-agent protocol with the contrast agent Gd-DTPA and the albumin-bound Gd-BOPTA. The small variability in the GFR values indicates that the measurement approach may be sufficiently precise to detect subtle variations in Gd-BOPTA relaxivity due to increased albumine leakage. This technique may help detecting such diseases in an early stage, where tubular reabsorption of albumine masks the leakage in urine samples. Further studies in a model with albumine leakage is warranted.

                  2685.     Counting Total Number of Kidney Glomeruli Using MRI

Scott Charles Beeman1, Megan Henriksen1, David Frakes1, Kevin M. Bennett1

1Bioengineering, Arizona State University, Tempe, AZ, United States

We present a method for counting number of renal glomeruli using MRI.  Rats were given intravenous injections of CF followed by resection of kidneys.  Ex vivo Imaging revealed spots of hypointensity throughout the cortex of the kidney due to accumulation of CF in the glomerular basement membrane, consistent with individual glomeruli.  Thresholding techniques applied to the image volumes yielded a glomerular count of 43,362 glomeruli.  This is in agreement with and lies within 10% of a histological count of 39,514 glomeruli in the contralateral kidney, indicating an accurate glomerular count of the whole kidney.

                  2686.     Segmentation of Kidney Cortex and Medulla on MR Images by Use of Multi-Feature K-Means Method

Yin Huang1, Deborah Yagow2, Nathan Artz1, Elizabeth Sadowski3, Arjang Djamali4, Sean Fain1

1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Nephrology, University of Wisconsin-Madison, Madison, WI, United States

The K-means segmentation method was implemented to automatically segment kidney cortex and medulla on MR images of 24 subjects based on two kidney feature values -- T1 and perfusion weighted information. Manual segmentation results on the same subjects were used as reference and three similarity measures were calculated to evaluate the effectiveness of K-means segmentation. The segmentation time was radically shortened by K-means compared with manual operation. However, there are about 30% of all subjects that K-means segmentation did not work well so that a semi-automated strategy can be suggested to incorporate manual segmentation when necessary.

                  2687.     Changes in Kidney Volume in Experimental PKD Quantified by a Clinical 3T MR Scanner

Sheryl Foster1, Mayuresh S. Korgaonkar2, Gopi K. Rangan3, Kristina G. Schwensen3, Anthony Peduto1

1Radiology, Westmead Hospital, University of Sydney, Australia; 2Brain Dynamics Center, Westmead Millennium Institute, Westmead, NSW, Australia; 3Centre for Transplant and Renal Research, Westmead Millennium Institute, University of Sydney, Australia

The goal of this study was to assess the feasibility of using a 3T whole body clinical scanner along with a conventional available wrist coil in a longitudinal study of drug treatment in small rodents. We studied longitudinal kidney structural changes in rodents with Polycystic Kidney Disease (PKD); and also evaluated the effect of sirolimus treatment, an immunosuppressant drug currently used in clinical trials in humans with PKD, during early disease on the progression of kidney enlargement in this animal model.

                  2688.     Comparison of DCE-MRI and DCE-CT in Patients with Renal Cell Carcinoma: Effects of Temporal Resolution and Total Measurement Time

Colleen Bailey1,2, Mostafa Atri3, Georg A. Bjarnason1, Greg J. Stanisz1,2

1Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2University of Toronto, Toronto, ON, Canada; 3University Health Network, Toronto, ON, Canada

Patients with renal cell carcinoma were scanned with DCE-MRI (temporal resolution 3.7 s) and DCE-CT (temporal resolution 1 s). ROIs across the tumour volume were analyzed using the Kety-Tofts two-compartment model of perfusion. The volume transfer constant, Ktrans, did not correlate between the two modalities. The extravascular extracellular volume, ve, showed weak correlation. Undersampling the DCE-CT data to similar temporal resolution as the DCE-MRI data systematically underestimated Ktrans, whereas restricting the DCE-MRI data, initially acquired over five minutes, to the two minute acquisition time of the DCE-CT data resulted in a systematic underestimation of ve and an overestimation of Ktrans.

                  2689.     Seminal Vesicle Dilatation in Autosomal Dominant Polycystic Kidney Disease

Beatriu Reig1, Jon Blumenfeld2,3, Stephanie Donahue3, Wei Zhang, Martin R. Prince

1Department of Radiology, Weill Cornell Medical College, New York, NY, United States; 2Department of Medicine, Weill Cornell Medical College; 3The Rogosin Institute

Seminal vesicle dilatation, a probable cause of infertility in men with autosomal dominant polycystic kidney disease (ADPKD), is characterized in this review of 47 male ADPKD patients undergoing MRI.  Comparison is made to a cohort of age-matched controls.

                  2690.     In Vivo Prediction of Spermatogenesis in Seminiferous Tubules Using High-Resolution Magnetic Resonance Imaging and Machine-Learning Techniques in Combination

Masayuki Yamaguchi1, Natsumaro Kutsuna2,3, Ryutaro Nakagami1,4, Akira Nabetani5, Atsushi Nozaki5, Mamoru Niitsu4, Seiichiro Hasezawa2,3, Hirofumi Fujii1,3

1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan; 3Institute for Bioinformatics Research and Development-Japan Science and Technology Agency, Chiyoda, Tokyo, Japan; 4Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 5GE Healthcare Japan, Hino, Tokyo, Japan

Seminiferous tubules are stratified epithelia composed of germ cells and Sertoli cells. They produce sperm and normally are 200E00μm in diameter. We have succeeded in visualizing rat seminiferous tubules on in vivo MRI using a 3T scanner. In addition, the machine-learning technique allowed automatic classification of testicular regions on MRI into normal and abnormal spermatogenesis in chemotherapy-induced injury in rat testes. If these techniques are implemented in clinics in the future, they will be a helpful tool in reproductive medicine for infertile males.

                  2691.     A Reference Region Tracer Distribution Model Analysis of Rat Penile Vascular Changes by DCE.

H. Carl Le1, Nelson Bennett2, Raanan Tal2, Dov Winkleman1, John Mulhall3, Jason Koutcher1,4

1Medical Physics, MSKCC, New York, NY, United States; 2Urology, MSKCC, New York, NY, United States; 3Surgery, MSKCC, New York, NY, United States; 4Medicine, MSKCC, New York, NY, United States

Sildenafil is effective in restoring penile blood flow in alleviating erectile function, a common side effect from radical prostatectomy. We have used DCE MRI to image rat corpora cavernosum post nerve injury with and without sildenafil treatment. The effect of sildenafil on the corpora cavernosal vascular volume changes are detected and can be used to monitor penile vascular health in clinic.

                  2692.     Quality of Proton Magnetic Resonance Spectroscopic Imaging (MRSI) with and Without an Endorectal Coil: A Phantom Study

Jian Wang1, Jian-ping Lu1, Tom W J Scheenen2

1Radiology, Changhai Hospital, Shanghai, China; 2Radiology, Radboud University Medical Centre Nijmegen, Nijmegen, Gelderland, Netherlands

The quality of data acquisition and post-processing of proton MRSI with and without an endorectal coil at 1.5T and 3.0T was assessed with the use of a prostate phantom. With fixed spine and body array surface coils and an endorectal coil, 3D MRSI was performed repeatedly with 1) all coils, 2) only endorectal coil and 3) only surface coils. The choline + creatine/citrate (CC/C) ratio of each voxel was semi-automatically calculated and compared between different coil use and field strengths. Significant differences in CC/C existed between different field strengths and different locations within the phantom, when these locations had large differences in magnetic field homogeneity.

                  2693.     Proton and Sodium MR Imaging of in Vivo Human Prostate Using Dual-Tuned Body and Endorectal Coils at 7T

Kyongtae Ty Bae1, Jung-Hwan Kim1, Alessandro Furlan1, Chan Hong Moon1, Bumwoo Park1, Tiejun Zhao2

1University of Pittsburgh, Pittsburgh, PA, United States; 2MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States

We have demonstrated the feasibility of 1H and 23Na imaging of in vivo human prostate using dual-tuned body surface Tx/Rx and endorectal Rx only coils. Our imaging technique was tested on normal human volunteers. Further improvement of this technique may facilitate the diagnosis of prostate cancer.

                  2694.     Quantitative MRI Assessment of Matrix Development in Cell-Seeded Natural Urinary Bladder Smooth Muscle Tissue-Engineered Constructs

Hai-Ling Margaret Cheng1,2, Syed S. Islam3, Yasir Loai3, Roula Antoon3, Marine Beaumont1, Walid A. Farhat3

1Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 3Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada

Cell-seeded natural tissue scaffolds hold promise for tissue-engineering large organs (e.g. the urinary bladder matrix for regenerating different tissue types). However, our understanding of cell-natural matrix interaction is limited, and its influence on MRI characterization is unknown. This study explores quantitative MRI at 1.5 T for investigating cell-matrix interaction and matrix development in a smooth muscle cell-seeded bladder model. Competing with cell presence was matrix degradation due to cell-released collagenase, noted for the first time and perhaps unique to natural matrices. Quantitative T1, T2, and diffusion measurements are consistent with collagen breakdown, with multicomponent T2 providing the best specificity.

                  2695.     The Acellular Matrix for Bladder Tissue-Engineering: A Quantitative MRI Study

Hai-Ling Margaret Cheng1,2, Yasir Loai3, Marine Beaumont1, Walid A. Farhat3

1Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 3Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada

Scaffolds derived from natural tissue acellular matrix (ACM) possess native biomechanical and biological properties difficult to achieve with synthetic materials. Despite their promise, ACM optimization is needed and remains in early development. This study investigates the bladder ACM, which is useful for regenerating various tissues, and effects of incorporating hyaluronic acid (HA), a natural biomaterial useful in tissue regeneration. Quantitative MRI measurements (T1, T2, diffusion) at 1.5 Tesla are consistent with HA presence and two-fold water uptake from HA incorporation, with multicomponent T2 distinguishing the two effects. These results provide baseline MRI data for studying further manipulation such as cell-seeding.