Breast MR: Diffusion, Spectra & High Field

14:00         4534.     Diffusion MR Breast Imaging: Correlation of ADC Values to the Prognostic Factors

Sunitha B. Thakur¹, David D. Dershaw², Dilip Giri³, Junting Zheng⁴, Chaya Moskowitz, Jessica Ferrara², Jason A. Koutcher¹, Elizabeth A. Morris²

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

Treatment decisions and determination of breast cancer prognosis have traditionally been based on pathologic parameters such as tumorsize and axillary-nodal status, tumor-grade, and the results of tumor markers mainly ER/PR and HER-2/neu. Here we present the clinical usefulness of Diffusion-weighted MRI and measurement of apparent diffusion coefficients (ADCs) to correlate traditional markers such as histology and molecular markers such as ER, PR and HER-2.  Mean tumor size is significantly higher in patients with positive lymph nodes. Although ADC values represent a valuable biomarker for detecting malignant lesions, the ADC cannot be a prognostic indicator for patients with breast cancer.

14:30         4535.     Post Lumpectomy MRI: Using Diffusion Weighted Imaging (DWI) to Distinguish Benign from Malignant Tissues

Frederick Kelcz¹, Kendra S. Hain¹

¹Radiology, University of Wisconsin, Madison, WI, United States

We reviewed diffusion imaging results in post lumpectomy patients and preliminary results show a consisent ADC value in the benign range, despite persistent, occasionly concerning enhancement.  DWI may be of great value in ruling in benignancy when differentiating enhancing scar from malignancy.

15:00         4536.     Diffusion MR Breast Imaging: ADC Values for Differentiating of Malignant from Benign Breast Tumors

Sunitha B. Thakur^1,2, David D. Dershaw², Dilip Giri³, Junting Zheng⁴, Chaya Moskowitz, Jason A. Koutcher^1,2, Elizabeth A. Morris²

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

Diffusion MRI is a noninvasive technique which provides information about early changes in morphology and physiology of tissues by monitoring changes in the local apparent diffusion coefficient (ADC) of water molecules. Recently, diffusion-imaging has demonstrated potential in discriminating malignant from benign breast tumors and in assessing progression of disease following therapy. In this work we present the clinical usefulness of DWI and ADC values. ADC measurements are useful to differentiate malignant lesions from benign lesions yielding 98.4 % specificity and 90.9 % sensitivity with ADC cut-off value of 1.28x10^-3 mm²/s. ADC was less reliable for differentiating invasive and non-invasive carcinomas.

15:30         4537.     Diffusion Weighted Imaging of the Breast: Can It Decrease the Number of Unneeded Biopsies?

Wafaa Raafat Abdel Hamid¹, Lobna Rashed Ezz El Arab, Mona Ahmed Mohamed², Yasser Abdel Azim Abbas

¹Radiodiagnosis, Ain Shams University, Cairo, Egypt; ²Johns Hopkins University school of medicine

Classic magnetic resonance imaging is based on the enhancement pattern of lesions in dynamic breast MRI and morphologic changes. However, there is an overlap of these criteria with benign lesions. Accordingly, problematic cases have always been subjected to biopsies and histopathological verification. In our work we are shedding light on the added value of Diffusion Weighted Imaging and ADC values in differentiating between benign and malignant breast lesions, with a major goal of sparing patients the invasiveness  and complications of unneeded biopsies.

13:30         4538.     Motion and Distortion Correction in Diffusion-Weighted MRI of the Breast at 3T

Lori R. Arlinghaus^1,2, E. Brian Welch^1,3, A. Bapsi Chakravarthy⁴, Jaime S. Farley⁵, John C. Gore^1,2, Thomas E. Yankeelov^1,2

¹Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; ³MR Clinical Science, Philips Healthcare, Cleveland, OH, United States; ⁴Radiation Oncology, Vanderbilt University, Nashville, TN, United States; ⁵Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN, United States

Diffusion-weighted imaging (DWI) is a promising surrogate biomarker for the characterization of human breast cancer.  However, DWI acquisition sequences are  susceptible to artifacts induced by subject motion and eddy currents.  DWIs acquired with echo planar imaging (EPI) techniques are also prone to nonlinear distortion induced by B₀ field inhomogeneities, which worsen as field strength increases.  We present evidence that image registration and B₀ field map correction improve the quality of apparent diffusion coefficient (ADC) maps derived from the DWI data and improve the registration of the DWI data with anatomical images for comparison with other parametric maps.

14:00         4539.     Operator Performance of Voxel Placement for Single-Voxel MRS of Breast Lesions

Naomi R. Mraz¹, Michael T. Nelson¹, Jessica Kuehn-Hajder¹, Greg John Metzger², Patrick John Bolan²

¹Radiology, University of Minnesota, Minneapolis, MN, United States; ²Radiology/CMRR, University of Minnesota, Minneapolis, MN, United States

In order for single-voxel MRS measurements to be a useful clinical tool for characterizing breast lesions, voxel placement must be accurate and consistent. This project tested the consistency of voxel placement between four different operators using a retrospective study to simulate voxel placement on a MR scanner. The relative geometric intersection was used as a measure of concordance between readers. Overall concordance was lower than expected (ranging 0%-82.5%, mean 31.2%). Concordance was higher for masses than for non-mass-like lesions. These results suggest that further training, guidance, or software support should be used to improve voxel placement consistency.

14:30         4540.     1H MR Spectroscopy of the Breast Cancer at 3.0-Tesla: Comparison Between Pre- And Post- Contrast Administration.

Hisashi Kawai¹, Shinji Naganawa¹, Hiroko Satake¹, Satoko Ishigaki¹

¹Radiology, Nagoya University, Nagoya, Japan

The purpose of this study was to assess whether VOIs of MRS were located properly with non-contrast MRI and to compare the variability between pre- and post-contrast spectroscopic measurements at 3T-MRI.

Single-voxel MRS were performed in 92 breast cancer lesions. In 52 lesions, MRS was obtained before and after contrast-enhanced MRI. VOI were located in the lesion properly in 74 out of 92 breast cancers. The integral value of choline peak decreased significantly in post-contrast MRS compared to in pre-contrast MRS. MRS should be obtained before contrast administration not to be affected by Gadolinium contrast agents.

15:00         4541.     The Impact of Gd-DTPA on Breast ¹H MRS

Patrick John Bolan¹, Eva H. Baker², Lance Jay DelaBarre¹, Hellmut Merkle³, Doug Yee⁴, Michael T. Nelson⁵, Lenore Everson⁵, Michael Garwood¹

¹Radiology/CMRR, University of Minnesota, Minneapolis, MN, United States; ²Diagnostic Radiology Department, NIH Clinical Center, Bethesda, MD, United States; ³National Institute Neurological Disorders and Stroke, NIH, Bethesda, MD, United States; ⁴Masonic Cancer Center, University of Minnesota, Minneapolis, MN, United States; ⁵Radiology, University of Minnesota, Minneapolis, MN, United States

While ¹H MRS is increasingly being used in clinical studies of breast cancer, there has been some evidence that the use of Gadolinium-based contrast agents prior to MRS can affect the spectra, broadening the choline resonance and reducing its area. This work describes a study performing ¹H MRS at 4T before and after a bolus of Gd-DTPA. It was found that after the contrast injection there was a small negative impact on both the choline and water peaks, with an effect size of 10-15%.

13:30         4542.     Measurement of the Breast Density Using IDEAL-Dixon Imaging at 3T

Sungheon Kim¹, Tess Clendenen², Sherlin Lavianlivi¹, Linda Moy¹, Henry Rusinek¹, Malcolm C. Pike³, Anne Zeleniuch-Jacquotte⁴

¹Center for Biomedical Imaging, Radiology, NYU School of Medicine, New York, NY, United States; ²Epidemiology, NYU School of Medicine, New York, NY, United States; ³Preventive Medicine, USC Keck School of Medicine, Los Angeles, CA, United States; ⁴Environmental Medicine, NYU School of Medicine, New York, NY, United States

This study was to assess if Dixon water/fat images could be used to monitor breast volume and density changes during the menstrual cycle. Reproducibility of the volume and density measurement was assessed with data from four subjects. In addition, five healthy premenopausal women were scanned once a week for four weeks. The median breast volume was smallest in the ovulatory phase and largest in the late luteal phase. FG density was lowest at the follicular phase and highest in the late luteal phase. This result demonstrates the feasibility of using Dixon imaging to monitor the change in the breast.

14:00         4543.     Quantitative Evaluation of Fat Suppression Techniques for Breast MRI at 3.0T

Chen Lin¹, Laurie Owens¹, Hal Kipfer¹, Helmuth Schultze-Haakh², Brian Dale²

¹Department of Radiology and Imaging Science, Indiana University School of Medicine, Indianapolis, IN, United States; ²Siemens Healthcare, Marlven, PA

Quantitative assessment of the quality of fat suppression in breast MRI with four different techniques, conventional quick fat (QFS), spectrally selective adiabatic inversion recovery (SPAIR), water only excitation (WE) and two point dixon (2PT DIXON) was made at 3.0T. The result demonstrates similar but inferior performance for QFS, SPAIR and WE. While 2PT DIXON is shown to provide superior fat suppression, further development is needed.

14:30         4544.     Determining the Sensitivity and Specificity of High Spatial Resolution 3.0T Breast MRI in a High Risk Familial Breast Cancer Screening Cohort

Martin D. Pickles¹, Lindsay W. Turnbull¹

¹Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom

Theoretically breast MR examinations at 3.0T should be superior to 1.5T studies. However, breast imaging on higher field strength systems also pose problems such as larger chemical shift, susceptibility artefacts, B1 inhomogeneities and increased T1 relaxation times. The aim of this work was to compare the sensitivity and specificity achieved by a 3.0T MR breast screening programme against the published results of screening studies at 1.5T. In conclusion the diagnostic accuracy of MR breast screening at 3.0T does not seem to be adversely effected by high field strength related artefacts and the results are comparable to those published at 1.5T.

15:00         4545.     Assessing the Accuracy of a Commercial Computer Aided Diagnosis Package (CADstream) in Determining the Level of Disease Post Neoadjuvant Chemotherapy in a Cohort of Breast Cancer Patients

Martin D. Pickles¹, Lindsay W. Turnbull¹

¹Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom

CADstream is a computer aided diagnosis package developed to aid in the interpretation of breast MR. Reports have demonstrated that CADstream provides quicker interpretation, increased specificity and greater correlation with histological size. However, these reports are based on the assessment of pre-treatment lesions and not post chemotherapy lesions where a treatment induced vascular shutdown is anticipated. The aim of this study was to assess CADstream’s accuracy post chemotherapy. In conclusion this study demonstrated by reducing the enhancement and difference thresholds the sensitivity can be increased resulting in fewer false negative results.

13:30         4546.     Breast BOLD Correlates to Optical Breast Imaging During Respiratory Stimulus

Colin Morehouse Carpenter^1,2, Rebecca Rakow-Penner³, Shudong Jiang², Brian William Pogue², Keith David Paulsen², Gary H. Glover³

¹Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States; ²Thayer School of Engineering at Dartmouth, Hanover, NH, United States; ³Radiology, Stanford University School of Medicine, Stanford, CA, United States

BOLD response in the breast was measured concurrently with MR-guided diffuse optical tomography (MRg-DOT) in 11 healthy volunteers during inspired gas changes. This approach utilized optical imaging to quantitatively identify the independent effects of oxy- and deoxyhemoglobin.  A key factor in this study was characterization of the background physiological noise variations in individual subjects, which was measured via optical imaging during air breathing. The results from this work indicate that BOLD and optically-determined deoxyhemoglobin signals correlate significantly in the breast during an oxygen/carbogen respiratory stimulus, as long as only subjects that exhibit a significant response are included.

14:00         4547.     MR Breast Density Measurement: Comparison of Two Anatomic Landmarks for Breast Segmentation

Jeon-Hor Chen^1,2, Shih-Ting Chen², Cheng-Ju Lin², Daniel Chang¹, Po-Pang Tsai², Ke Nie¹, Orhan Nalcioglu¹, M-Y Lydia Su¹

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

Although breast density measurement showed high correlation using both anatomic landmarks, there was still an average of 20% difference for FV measurement. A significant number of women had the problem of being cut off of their fibroglandular tissue when the pectoris major muscle was used as the landmark. From our study, it was concluded that in women with dense breast such as the subjects included in this study, both anatomic landmarks, especially the one anterior to the pectoris major muscle, will have the problem of cut-off of the fibroglandular tissue, resulting in the acquired  fibroglandular tissue underestimated.

14:30         4548.     Comparison of Breast Density Measured on Fat-Suppressed Versus Non-Fat-Suppressed MRI

Daniel Han-en Chang¹, Jeon-Hor Chen^1,2, Shadfar Bahri¹, Hon J. Yu¹, Ke Nie¹, Orhan Nalcioglu¹, Min-Ying Lydia Su¹

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

Mammographic density is known to be strongly associated with the risk of breast cancer development, but using mammography to characterize breast density does not provide true volumetric information. MRI-based methods on the other hand provide promising alternatives, but may be affected by technical factors such as the choice of pulse sequences. We imaged breasts with two commonly used pulse sequences, fat-suppression and non-fat-suppression, and calculated their densities with an MRI-based method developed previously by our lab. We found that their densities are highly correlated and that fat-saturated images tend to have stronger relative tissue contrast.

15:00         4549.     Correction of Skin Volume in the Breast Density Measured by MRI

Ke Nie¹, Daniel Chang¹, Jeon-Hor Chen^1,2, Tzh-Ching Shih^1,2, 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

There is a great interest to correlate between the density measured on MRI and mammogram, so the established role for mammographic density may be extended to MRI-based density. One problem specific to volumetric MRI analysis is the inclusion of skin as the dense tissue. In contrast this effect could be ignored on projection mammogram. In this study, we investigated the correlation between the volume of the skin and the breast on 3D MRI. We further provided two correction models aiming to provide an estimation of the skin volume and its effect on MRI based density measurement.

Breast MR

14:00         4550.     Contrast-Enhanced 1.5-T MR Imaging of the Breast: Association Between Asymmetric Increase of Whole Breast Vascularity and Ipsilateral Cancer on a Series of 384 Studies - not available

Luca Alessandro Carbonaro¹, Nicola Verardi, Henrida Kule, Giovanni Di Leo, Francesco Sardanelli¹

¹Unit of Radiology, Università degli Studi di Milano, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy

We estimated the value of the breast vascular map asymmetry (BVMA) as a marker of ipsilateral tumors. Three-hundred-eighty-four patients underwent a dynamic study. We looked for BVMA. Pathologic examination or follow-up served as a reference standard. Pathology revealed 173 malignant lesions and 211 benign lesions. BVMA showed high diagnostic performance. Sensitivity was 76% for invasive cancers and 39% for in-situ cancers (P<0.001). Breast vascular map asymmetry was associated with ipsilateral cancer in 76% of invasive tumors, only in 39% of DCIS. For ¡Ý20-mm tumors, a 90% association was found.

14:30         4551.     Feasibility of the Usage of the Internal Mammary Artery as an Artery Input Function in Pharmacokinetic Analysis Using the Contrast Enhanced Dynamic MR Study in Breast Tumor

In Chan Song¹, Nariya Cho¹, Yong Sik Bang¹, Woo Kyung Moon¹

¹Department of Radiology, Seoul National University Hospital, Seoul, Chongno-gu, Daehangno 101, Korea, Republic of

We evaluated a feasibility of the usage of internal mammary artery near chest wall as an artery input function in contrast enhanced dynamic MR study to obtain the permeability map in breast tumor. Ktrans and Kep were successfully measured using the internal mammary artery as an artery input function based on the Tofts model in all patients. In breast tumor, the good performance in fitting procedure and the acquired two parameters showed that the internal mammary artery may be used as an artery input function in pharmacokinetic analysis.

15:00         4552.     Breast MRI Using a Balanced Steady-State Free Precession Imaging with a Two-Point Dixon Fat-Water Reconstruction Algorithm: Preliminary Experience and Comparison with 2D FSE

Christine Lee¹, Manoj Saranathan², Gina Hesley¹, Robert Maxwell¹, Kathy Brandt¹

¹Mayo Clinic, Rochester, MN, United States; ²Applied Science Lab, GE Healthcare, Rochester, MN, United States

Clinical evaluation of an ultrafast T2-like acquisition with near isotropic resolution in breast MRI is compared to more conventional 2D Fast Spin Echo.

15:30         4553.     Breast MRI Using TWIST: Doubling the Spatial Resolution “for Free”

Rolf Janka¹, Evelyn Wenkel¹, Christian Geppert², Berthold Kiefer², Michael Uder¹

¹Radiology, Universitity of Erlangen, Erlangen, Bavaria, Germany; ²Siemens Medical Solutions

The TWIST sequence divides k-space in two radial regions and samples it using a pseudo-stochastic trajectory at adjustable density. While the central region is sampled at the full temporal resolution, the periphery is sampled with reduced density. Its main field of application is an increase of temporal resolution in MR-angiography. But it can also be used to increase spatial resolution in the dynamic sequence of breast MRI. We tested the new sequence in 61 women and think it is a reliable and powerful tool in breast imaging which fulfil the requirements of both high temporal and spatial resolution.

13:30         4554.     Using T2-Weighted MRI in the Automated Analysis of Breast Cancer Lesions - not available

Neha Bhooshan¹, Maryellen Giger¹, Li Lan¹, Angelica Marquez², Hui Li¹, Gillian Newstead¹

¹University of Chicago, Chicago, IL, United States; ²Loyola University, Chicago, IL, United States

This study’s purpose was to investigate the automated analysis of T2-weighted MR images in distinguishing malignant and benign breast lesions.  Using 86 benign and 110 malignant lesions, our CADx scheme automatically performed lesion segmentation, feature extraction, and classification.  T2 morphological features yielded an AUC of 0.78± 0.03 while T1 kinetic and morphological features achieved an AUC of 0.83± 0.03.  When considering all features, two T2 features, three T1 features and one geometric feature were selected, giving an AUC of 0.85± 0.03.  T2 MRI has the potential to improve the performance of CADx in distinguishing malignant and benign breast lesions.

14:00         4555.     Incidental Enhancing Lesions Found on Preoperative Breast MRI: Management and Role of Second Look Ultrasound

Maria Laura Luciani¹, Federica Pediconi, Valeria Dominelli, Marianna Telesca, Valeria Casali, Federica Vasselli, Carlo Catalano, Roberto Passariello

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

We evaluated the role of second look US for the study of occasional lesions detected on preoperative breast MRI and we proved it can be an helpful way to localize and study lesions depicted only on preoperative breast MRI.

14:30         4556.     Correlation of Prognostic Parameters and MR Perfusion Parameters in Dynamic Contrast Enhanced MRI (DCE-MRI) in Patients with Breast Cancers

Nariya Cho¹, In Chan Song¹, Yong Sik Bang¹, Woo Kyung Moon¹

¹Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of

Transfer constant obtained from DCE-MRI are well correlated with tumor size and histologic grade of breast cancer, which shows its potential as a noninvasive prognostic parameter in the breast cancer patient.

15:00         4557.     The Evaluation of the Disease Extent in Patient with Ductal Carcinoma in Situ: Comparison of Mammography, Sonography, and MRI - not available

Kyoung Eun Lee¹, Hak Hee Kim¹, Jeong-Hee Sohn¹, Hee Jung Shin¹, Gyungyub Gong², Se Hyun Ahn³, Hyeon Sook Kim⁴, Eun Suk Cha⁴

¹Radiology, Asan Medical Center, Seoul, Korea, Republic of; ²Pathology, Asan Medical Center, Seoul, Korea, Republic of; ³General Surgery, Asan Medical Center, Seoul, Korea, Republic of; ⁴Radiology, The Catholic University of Korea, Seoul, Korea, Republic of

We think that in patient with DCIS, complemented MRI may be best establish the presence and extent of disease.

13:30         4558.     Multifunctional MRI to Detect and Localize Multifocal and Multicentric Breast Cancer

Elizabeth O'Flynn¹, Anna Kirby², Maria Schmidt¹, Ashutosh Nerurkar³, Veronica A. Morgan¹, Erica Scurr¹, John Yarnold², Nandita M. deSouza¹

¹Cancer Research UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ²Clinical Academic Radiotherapy, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ³Histopathology, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

This pilot study demonstrates the accuracy of dynamic contrast-enhanced (DCE)-MRI and diffusion-weighted (DW)-MRI in detecting and localising multifocal and multicentric disease in patients with breast cancer by correlating imaging with histopathology findings at mastectomy. DCE-MRI alone was most accurate in detecting satellite lesions (sensitivity of 89%), DW-MRI was least accurate (sensitivity 55%). Satellite lesions were found up to 22 mm from the edge of the index lesion. Accurate identification of satellite lesions with multifunctional MRI offers potential for monitoring the effects of local therapies on multifocal and multicentric disease, and in defining the target volume for partial breast irradiation.

14:00         4559.     Magnetic Resonance Imaging for Axillary Staging in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy: Comparison with Ultrasonography and Positron Emission Tomography - not available

Sun Mi Kim¹, Chae Yeon Lyou¹, Mijung Jang¹

¹Seoul National University Bundang Hospital, Seongnam-Si, Gyunggido, Korea, Republic of

The presence of axillary lymph node(LN) metastases in breast cancer is an important factor in assessing prognosis and determines management. Although surgical biopsy remains the gold standard for the diagnosis of axillary LN metastasis but standard for surgical biopsy in monitoring for chemotherapy response does not established yet. Comprehensive and sequential staging of axilla using noninvasive diagnostic modalities has been approached and which would represent an importance advance in the management of breast cancer patients. This presentation evaluate the accuracy of comprehensive pre- and post-neoadjuvant chemotheraphy axillary staging via MRI, ultrasound imaging and positron emission tomography.

14:30         4560.     MRI Findings of Triple Negative Breast Cancer: A Comparison with Non Triple Negative Breast Cancer

Jae Jeong Choi¹, Sung Hun Kim², Eun Suk Cha³, Hyun Suk Kim⁴, Jae Young Byun², Bong Joo Kang², Ji Hye Lee²

¹Radiology, Seoul St. Mary's Hospital, Catholic University of Korea , Seoul, Korea, Republic of; ²Radiology, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea, Republic of; ³Radiology, St. Vincent's Hospital, Catholic University of Korea, Seoul, Korea, Republic of; ⁴Radiology, St. Paul's Hospital, Catholic University of Korea, Seoul, Korea, Republic of

We would like to submit our report titled ¡°MRI Findings of Triple Negative Breast Cancer: A Comparison with Non Triple Negative Breast Cancer¡¯¡¯. Triple negative breast cancer is a subtype with aggressive clinical behavior which currently lacks effective targeted therapies. MRI characteristics of triple negative breast cancer could assist pretreatment planning and prognosis assessment. We evaluated MRI and clinicopathologic features of triple negative breast cancer, and compared them with those of non triple negative breast cancer.

15:00         4561.     Multiparametric MR Measurement of Menstrual Variation in the Breast

Sungheon Kim¹, Linda Moy¹, Malcolm C. Pike², Anne Zeleniuch-Jacquotte³, Tess Clendenen⁴

¹Center for Biomedical Imaging, Radiology, NYU School of Medicine, New York, NY, United States; ²Preventive Medicine, USC Keck School of Medicine, Los Angeles, CA, United States; ³Environmental Medicine, NYU School of Medicine, New York, NY, United States; ⁴Epidemiology, NYU School of Medicine, New York, NY, United States

The purpose of this study was to develop a multiparametric MRI method to investigate magnitude and timing of various breast changes during the menstrual cycle. Five healthy premenopausal women were scanned once a week for four weeks. T2, ADC, and magnetization transfer rate were measured. T2 gradually increased throughout the cycle and was 5% higher in the menstrual phase than the follicular phase. In contrast, the median ADC was highest in the luteal phase (15% greater than the follicular phase) and began to decline during menses. The MTR was about 4% lower in the menstrual phase than the follicular phase.

Fetal & Female Pelvis

13:30         4562.     Time-Resolved MR Angiography in the Detection of Ovarian Venous Reflux

Dal Mo Yang¹, Dong Ho Lee², Dong Wook Sung², Geon-Ho Jahng, Chang Woo Ryu

¹Radiology, East-West Neo Medical Center, Kyung Hee University, Seoul, Korea, Republic of; ²Radiology, Kyung Hee University Hospital

The purpose of this study was to compare the diagnostic accuracy of time-resolved MR angiography with that of conventional angiography for detection of ovarian venous reflux, which aid for a diagnosis of pelvic venous congestion. Retrospective analysis was performed with 19 consecutive patients who underwent time-resolved MR angiography and conventional angiography. There was no significant difference between time-resolved MR angiography and conventional angiography for detection of ovarian venous reflux (P > 0.05). The sensitivity, specificity, and diagnostic accuracy of time-resolved MR angiography were found to be 93.5%, 66.7%, and 89.5%, respectively. Time-resolved MR angiography is helpful for diagnosis of pelvic venous congestion.

14:00         4563.     Magnetic Resonance Imaging and Ultrasonography in Diagnosis of Pelvic Vein Thrombosis During Pregnancy

Michael R. Torkzad¹, Katarina Bremme², Margareta Hellgren³, Maria J. Eriksson⁴, Anna Hagman⁵, Trine Jörgensen², Kent Lund⁴, Gunnel Sandgren⁶, Lennart Blomqvist⁷, Peter Kälebo⁸

¹Radiology Department, Uppsala University Hospital, Stockholm, Sweden; ²Karolinska Institutet, Woman and Child Health, Stockholm, Sweden; ³The Sahlgrenska Academy, University of Gothenburg, Institute for the Health of Women and Children, Gothenburg, Sweden; ⁴Karolinska Institutet, Department of Clinical Physiology, Stockholm, Sweden; ⁵The Sahlgrenska Academy, Institute for the Health of Women and Children, Gothenburg, Sweden; ⁶Sahlgrenska University Hospital/Östra, Department of Clinical Physiology, Gothenburg, Sweden; ⁷Department of Diagnostic Radiology, Karolinska University Hospital Solna, Department of Diagnostic Radiology, Stockholm, Sweden; ⁸Sahlgrenska University Hospital/Östra, Department of Radiology, Gothenburg, Sweden

Purpose: The agreement between ultrasonography and magnetic resonance imaging (MRI) in diagnosing the extent of pelvic deep vein thrombosis (DVT) during pregnancy was measured. Materials and methods Pelvic veins of 27 pregnant women with DVT were examined with ultrasound and MRI. Results: Three cases (11.5%) of DVT in the pelvic veins were shown only on MRI. MRI was able to detect highr thrombus extension in 65% of cases. Proportion of agreement (ê) between ultrasound and MRI for DVT in individual veins was 0.33 (95% CI 0.27-0.40, i.e. fair agreement). Conclusion: MRI could be essential in diagnosis of pelvic DVT during pregnancy.

14:30         4564.     Assessment of Placental Blood Flow Using a Navigator Echo Respiratory Gated Parallel Imaging Technique at 1.5 T

Loredana Sorina Truica¹, Ian Cameron, ^1,2, Leonard I. Avruch², Andre Gruslin²

¹Carleton University, Ottawa, ON, Canada; ²The Ottawa Hospital, Ottawa, ON, Canada

IVIM measurements of normal placenta at 1.5 T using a respiratory triggered DW_SS_EPI sequence are reported. Improvements in the acquisition and analysis techniques used in this study allowed us to obtain more consistent results for the perfusion fraction, f, the diffusion coefficient, D, and the pseudo-diffusion coefficient, D*, than previous studies. Parameter maps of D and f were reflective of placental structure and composition. Such maps can be useful tools in identifying tissue differences and give important insight into the placental hemodynamic systems. This technique could become instrumental in the assessment and management of abnormal pregnancies.

15:00         4565.     Isotropic 3D T2-Weighted MR Imaging for Female Pelvis with 3 Tesla MRI: Feasibility Study

Junko Takahama¹, Satoru Kitano¹, Aki Takahashi¹, Nagaaki Marugami¹, Megumi Takewa¹, Takahiro Itoh¹, Toshiaki Taoka¹, Kimihiko Kichikawa¹

¹Radiology, Nara Medical University, Kashihara, Nara, Japan

The aim of this study was to compare the quality of images obtained with 3D T2-weighted sequence with the quality of conventional 2D T2-weighted images on 3.0-T MRI. Thirty consecutively registered patients were reviewed and analyzed quantitative measures of contrast and image quality. Three-dimensional volumetric T2-weighted images on 3.0T MRI are of content quality and give better anatomical recognition than conventional 2D images and have the added advantage of multiplanar and postprocessing capabilities.

MR Upper Abdomen I

14:00         4566.     Semi-Quantitative Analysis of Normal Pancreas and Pancreatic Carcinoma with Dynamic Contrast-Enhanced MR Imaging on a 3.0T System

Xiao Hong Ma¹, Chun Wu Zhou¹, Fei Sun², Xin Ming Zhao¹, Han Ouyang¹, Hong Mei Zhang¹

¹Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China; ²Shanghai Guided Medical Scientific Co. Ltd., Shanghai, China

Our study target to semi-quantify the perfusion parameters of normal pancreas and pancreatic carcinoma with three-dimension (3D) high spatial and time resolution dynamic contrast enhanced (DCE) MRI on a 3.0T MR system. 31 patients who need abdomen contrast enhancement scan but with normal pancreas and 34 pancreatic carcinoma patients underwent DCE-MRI on a 3.0T MR system with 8-channel body coil. The perfusion parameters were measure including signal enhancement ratio at 30 seconds and 90 seconds after injection (SER30, SER90), positive enhancement integral (PEI), time to peak (TTP) and maximum slope of increase (MSI). There is no regional perfusion difference between the head, body and tail of normal pancreas, while there is significant difference between lesion and non-lesion area of pancreatic carcinoma, and between normal pancreas and non-lesion area of pancreatic carcinoma.

14:30         4567.     Effects of Oxygen Inhalation on T1 Relaxation Times in Abdominal Solid Organ

Kyung Ah Kim¹, Mi-Suk Park¹, Eun Ju Kim², Myeong-Jin Kim¹, Jin-Young Choi¹, Hye-Suk Hong¹, Ki Whang Kim¹

¹Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of; ²Clinical science, MR, Philips Healthcare, Seoul, Korea, Republic of

We investigated the effect of the oxygen inhalation on relaxation times of T1 in abdominal solid organs, including liver, pancreas, spleen, and kidney. The inhalation of oxygen caused T1 shortening in the pancreas, kidney and spleen, which have predominant arterial blood supply, whereas no significant effect was noted in the liver, which has predominant portal venous blood supply. Our results indicate that MRI is feasible to detect changes with oxygen inhalation, which differs considerably among organs, in a noninvasive fashion. As a clinical application, the effect of oxygen on various normal and pathologic tissues may be used as a biomarker of arterial flow, oxygen delivery to organs, and hypoxic status.

15:00         4568.     Aged Vs. Fresh Blood for the Treatment of Hemorrhagic Shock; Differential Effect on Liver Outcome and Possible Mechanism

Idit Matot¹, Miriam Katz², Orit Pappo³, Nathalie Corchia⁴, Gregory Barshtein⁵, Shaul Yedgar⁵, Rinat Abramovitch, ⁶

¹Department of Anesthesiology & Intensive Care, Tel Aviv, Sourasky Medical Center, Tel Aviv, Israel; ²Department of Anesthesiology, Rabin Medical Center, Petach Tiqva, Israel; ³Pathology, Hadassah Hebrew University Medical Center, Jerusalem, Israel; ⁴he Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel; ⁵Department of Biochemistry, Hebrew University, Jerusalem, Israel; ⁶MRI/MRS lab HBRC, Hadassah Hebrew University Medical Center, Jerusalem, Israel

Concerns have recently been raised about the safety of transfusing stored-blood. Several studies have suggested that the risk of complications increases when transfused blood has been stored for long period. The liver is a target for injury in low flow states associated with trauma and hemorrhage. We studied the effect of blood resuscitation (fresh vs. Stored-blood) on liver injury. In rats, transfusion of blood stored longer than 4 days increased liver injury. This was associated with significant changes in the viscoelastic characteristics of the stored-blood and unrelated to the oxygen-carrying-capacity, cytokines in the stored-blood or the RBC/endothelial cells adherence properties.

15:30         4569.     Characterization of Cirrhotic Nodules with Gadoxetic Acid-Enhanced MR Imaging: The Efficacy of Hepatocyte-Phase Imaging

Chen-Te Chou^1,2, Ran-Chou Chen^2,3

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

The study was to evaluate the efficacy of hepatocyte-phase imaging in characterization of focal hepatic lesions among cirrhotic liver using gadoxetic acid enhanced MRI. Our results revealed SNRs/CNRs of HCC were significantly decreased in hepatocyte phase (P<0.05) and the benign DN showed no significant difference (P>0.05). Severe additional HCC were diagnosed by hepatocyte-phase imaging. The diagnostic performance is significantly higher in the imaging set with hepatocyte-phase imaging (P=0.016). In conclusion, combination of gadoxetic acid-enhanced dynamic study and hepatocyte-phase imaging could provide better diagnostic performance than dynamic study only in characterization of focal liver lesion among cirrhotic liver.

13:30         4570.     Gd-EOB-DTPA Enhanced MR Imaging of the Liver: Correlation with Morphological Severity of Cirrhosis and Hepatic Parenchyma Enhancement at Hepatobiliary Phase

Atsushi Higaki¹, Tsutomu Tamada¹, Akihiko Kanki¹, Yasufumi Noda¹, Hiroki Higashi¹, Takenori Yamashita¹, Katsuyoshi Ito¹

¹Radiology, Kawasaki Medical School, Kurashiki, Okayama, Japan

We evaluated the relationships between enhancement effects of liver parenchyma in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhanced MR imaging and MR imaging findings of cirrhosis change. Hepatic parenchymal enhancement in the HP of Gd-EOB-DTPA enhanced MR imaging did not necessarily decrease according to the morphological severity of cirrhosis. This fact may suggest that the hepatic uptake of Gd-EOB-DTPA depends on the preserved hepatocytes function rather than the severity in morphologic changes in cirrhosis.

14:00         4571.     Diffusion-Weighted MR Imaging Improves Sensitivity of Lesion Detection Compared with Gadolinium Enhanced T1-Weighted Imaging in Patients with Suspected Liver Metastases from Neuroendocrine Tumours.

Mark Ingram¹, Toni Wallace², Erica Scurr², David J. Collins^2,3, Val Lewington⁴, Dow-Mu Koh²

¹Department of Radiology, St George's Healthcare NHS Trust, Tooting, London, United Kingdom; ²Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ³CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; ⁴Department of Nuclear Medicine, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

In patients with neuroendocrine liver metastases, imaging determination of the size and distribution of metastatic disease is of value as it could influence the choice of therapy. We compared diffusion-weighted MR imaging (DW-MRI) and gadolinium-DTPA enhanced MR imaging for the detection of focal liver lesions in patients with suspected liver metastases arising from neuroendocrine tumours. DW-MRI was found to have a significantly higher diagnostic sensitivity (88%) compared with gadolinium-DTPA enhanced MR imaging (77%) for lesion detection in this patient population (p = 0.001, McNemar test).

14:30         4572.     How to Reduce So-Called Ringing Artifacts in Primovist-Enhanced MR Imaging

Akihiro Tanimoto¹, Nobuya Higuchi², Akihisa Ueno², Shigeo Okuda²

¹Department of Diagnostic Radiology, School of Medicine, Keio University , Tokyo, Japan; ²Department of Diagnostic Radiology, School of Medicine, Keio University, Tokyo, Japan

So-called �gringing artifacts�h are often associated with Primovist-enhanced dynamic MR imaging, aggravating the diagnosis for focal hepatic lesions.  To analyze the cause of this phenomenon, various scan and data acquisition parameters were tested using a newly created simulation software on the personal PC.  The simulation study revealed that square matrices, short scanning time, slow infusion rate, and sequential view ordering were effective measures to reduce the artifacts.  These results were confirmed in the clinical practice of Primovist-enhanced MR imaging.

15:00         4573.     Initial Clinical Experience with FRFSE Triple Echo Dixon (FRFTED) for Breath-Hold Fast Dixon Abdominal MR Imaging

Russell Norman Low^1,2, Jingfe Ma³, Neeraj Panchal^1,2

¹Sharp and Children's MRI Center, San Diego, CA, United States; ²San Diego Imaging, San Diego, CA, United States; ³Department of Imaging Physics, The University of Texas MD Anderon Cancer Center, Houson, TX, United States

This study evaluates a prototype breath hold fast recovery fast spin echo (FSE) based Dixon pulse sequence that provides superior fat suppression less sensitive to magnetic field inhomogeneities.

13:30         4574.     Evaluation of a Non-Enhanced MRI Protocol Compared to Gadolinium-Enhanced MRI for Hepatocellular Carcinoma

Andrew Dean Hardie¹

¹Radiology, Medical University of South Carolina, Charleston, SC, United States

MRI is accurate for identifying hepatocellular carcinoma however gadolinium chelates are contraindicated in patients with severe renal dysfunction due to the risk of Nephrogenic Systemic Fibrosis. There is a need to develop clinically usefull non-contrast MRI techniques to image these patients. Diffusion-weighted imaging and T2* weighted imaging offer the ability to identify tumors in cirrhotic patients with an accuracy similar to gadolinium MRI.

14:00         4575.     Evaluation of a New Multi-Modality Visualization Tool for Investigation of Hepatic Metastases from Colorectal Cancer

Laurent Milot¹, Kayan Ma², Erin Efford¹, Gal Sela², Carolyn Maloney¹, Susan Crisp¹, Natalie Coburn³, Masoom Haider¹, Cameron Piron², Calvin Law³, Don Plewes⁴

¹Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; ²Sentinelle Medical Inc, Toronto, Ontario, Canada; ³Department of Surgical Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; ⁴Department of Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Ultrasound and MRI provide complimentary information useful in pre-operative planning for surgical resection of hepatic metastases from colorectal cancer. This study investigates the value of real-time co-registration of preoperative MRI and ultrasound images to determine if this method improves the ability to localize suspicious targets under ultrasound, using MRI as a gold standard. Co-registered MRI/ultrasound imaging yielded a significant increase in the number of targets successfully localized compared to ultrasound examination alone. Co-registered imaging was particularly effective in localizing small lesions (less than 5 mm) which were difficult to identify under conventional ultrasound examination.

14:30         4576.     Pharmacokinetics and Safety of Gadobenate Dimeglumine in Patients from 2 to 5 Years of Age

Gianpaolo Pirovano¹, Mieczyslaw Pasowicz², Miles A. Kirchin³, Ningyan Shen⁴, John R. Parker⁵, Alberto Spinazzi¹

¹Medical Affairs, Bracco Diagnostics Inc., Princeton, NJ, United States; ²Radiology, John Paul II Hospital, Kracow, Poland; ³Medical Communications, Bracco Imaging, Milan, Italy; ⁴Biometrics, Bracco Diagnostics Inc., Princeton, NJ, United States; ⁵Medical Communications, Bracco Diagnostics Inc., Princeton, NJ, United States

15 subjects aged 2-5 years were enrolled in a pharmacokinetic study and received 0.1 mmol/kg bw gadobenate dimeglumine.  Pharmacokinetic parameters were calculated from the blood Gd concentration-time data using compartmental and noncompartmental techniques. At 6 hours after gadobenate dimeglumine administration, all subjects¡¦ residual Gd in blood was close to 1.0 ƒÝg/mL, indicating that Gd was successfully cleared from the blood. No differences in whole blood or urinary pharmacokinetic parameters were observed between pediatric subjects 2 to 5 years when compared to adult subjects studied in previously.

15:00         4577.     MRI of Infiltrative HCC- Characterization of Imaging Features in Association with Clinical Presentation

Bobby Kalb¹, Douglas Vander Kooi², Daniel Karolyi¹, Bhavika Patel¹, Khalil Salman¹, Diego R. Martin¹

¹Radiology, Emory University, Atlanta, GA, United States; ²Radiology, Langley Airforce Base, Hampton, VA, United States

Infiltrative-type of HCC (I-HCC) is an incurable, less common growth pattern of HCC that may mimic fulminant CLD.  Distinction of I-HCC on MRI is critical for optimal management and to avoid inadvertent transplantation of incurable disease, however imaging features may be atypical with poor visibility of tumor extent on postcontrast images. We have categorized MR imaging and pathologic features of I-HCC, and found tumor conspicuity to be most pronounced on T2-weighted images, with portal venous tumor thrombus present in all cases. These findings are important to help improved clinical application of MRI in the setting of CLD.

13:30         4578.     Computational Analysis of Flow in the Portal Vein of Normal Subjects and Patients Using MRI and CFD

Stephanie M. George¹, Diego R. Martin², Don P. Giddens¹

¹Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States; ²Department of Radiology, Emory University School of Medicine, Atlanta, GA, United States

With the incidence of chronic liver disease (CLD) increasing the need for improved diagnostic measurements has increased.  Magnetic resonance imaging (MRI) and phase-contrast MR offer noninvasive techniques which provide both high quality anatomical and hemodynamic data.  The use of these data coupled with computational fluid dynamics (CFD) to provide detailed flow field information is a novel approach.   This study examines a small number of normal subjects and patients comparing PC-MR measured portal venous hemodynamic parameters including velocity and flow rate and computational results.  This work demonstrates the feasibility of coupling MRI and CFD to investigate the altered hemodynamics in CLD.

14:00         4579.     Relationship Between Gd-EOB-DTPA MRI and Tc-99m-GSA for Quantitative Evaluation of Liver Function

Jumpei Suyama¹, Shouei Sai¹, Masaaki Kawahara¹, Yoshimitsu Ohgiya¹, Noritaka Seino¹, Masanori Hirose¹, Takehiko Gokan¹

¹Department of Radiology, Showa University School of medicine, TOKYO, Japan

The purpose of this study is to evaluate relationship between Tc-99m-GSA scintigraphy and 3T-MRI using Gd-EOB-DTPA for quantitative liver function. Nineteen patients with liver tumor were included in this study. There was significant correlation between LHL15 and the increased ratio of signal intensity at 4min (r=0.80, p<0.00005), and the increased ratio at 20 min were also well correlated (r=0.67, p<0.0005). It could be possible to use Gd-EOB-MRI for quantitative liver function as well as Tc-99m-GSA scintigraphy.

14:30         4580.     In Vivo Imaging of Mouse Pancreas Utilizing Ultra High Field of 14T and Manganese Enhanced MRI

Riikka J. Immonen¹, Smaragda Lamprianou², Laurent Lecomte¹, Laurent Vinet², Paolo Meda², Rolf Gruetter^1,3

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/Lausanne, CH-1210/CH-1015, Switzerland

In vivo imaging of pancreas with high resolution is challenging. In diabetes pancreatic β–cell mass and function are gradually lost. MRI methodology to monitor this in vivo is needed. We utilized 14.1T and manganese enhanced MRI to image the mouse gland in vivo, and to examine the changes in manganese signal during β–cell stimulation by glucose. In multi-slice images with 50*50*300μm resolution, acquired <20min, we were able to distinguish pancreatic main vessels and exocrine ducts, and Mn highlighted spots, possibly pancreatic islets. We also demonstrated with T1-wt inversion recovery, lower resolution technique, the manganese enhancement before and after glucose stimulus.

15:00         4581.     Proton MRS of Hepatic Ischemia/Reperfusion Injury in an Experimental Rat Model

April M. Chow^1,2, Kannie W.Y. Chan^1,2, Shu Juan Fan^1,2, Jerry S. Cheung^1,2, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China

Hepatic ischemia/reperfusion injury (IRI) occurs during liver transplantation, tumor resection, hemorrhagic shock and veno-occlusive disease. Biochemical changes caused by hepatic IRI lead to hepatocellular remodeling, including cellular regeneration or irreversible programmed cell death. In this study, we demonstrated that the alteration in the metabolism of choline-containing compounds (CCC) accompanied with hepatic IRI could be monitored using ¹H MRS. The CCC peak may be useful in evaluating the regeneration of hepatocytes upon hepatic IRI. ¹H MRS has shown to be a potential tool for identify and quantify metabolic changes in liver in vivo noninvasively.

MR Upper Abdomen II

14:00         4582.     Gd-EOB-DTPA Enhanced-MRI of the Liver: Dynamic Enhancement Compared with Gd-DTPA, Preliminary Experience

Natasha Wehrli¹, Hersh Chandarana¹, Ely Felker¹, Bachir Taouli, ^1,2

¹NYU Medical Center, New York, NY, United States; ²Mount Sinai School of Medicine, New York, NY, United States

Gd-EOB-DTPA is a recently FDA approved liver-specific contrast agent which combines a dynamic and a delayed phase of enhancement, approved to be used at a lower dose compared to extracellular agents (0.025 vs. 0.1 mmol/kg). In this study, we compared hepatic vascular conspicuity obtained with single and double dose Gd-EOB vs. Gd-DTPA at the dynamic phase, and found significantly better liver-to-vessel contrast ratio with Gd-DTPA compared to single dose Gd-EOB-DTPA. The liver-to-vessel contrast ratio improved when using a double dose Gd-EOB-DTPA.

14:30         4583.     Tracer-Kinetic Analysis of Gd-EOB-DTPA in the Liver with a Dual-Inlet Two-Compartment Uptake Model

Steven Sourbron¹, Wieland Sommer, Christoph Zech, Maximilian Reiser, Karin Herrmann

¹Ludwig-Maximilian-University Munich, Munich, Bavaria, Germany

A dual-inlet one-compartment uptake model is developed for DCE-MRI with Gd-EOB-DTPA in the liver. The model generalizes the one-compartment model for the liver, providing one new parameter: the intracellular uptake rate (KI). Data in normal appearing liver tissue of 25 patients shows that the uptake model fitted all ROI curves accurately, and provided values in the expected range for all known parameters. The average value for KI was 1.7/100/min, with a relatively narrow range of normality. The method may present a new and practical paradigm in functional liver MRI, producing quantitative measures of both perfusion and hepatobiliary function.

15:00         4584.     Free-Breathing Dynamic Contrast-Enhanced Abdominal Imaging Using Navigator Gating and Adaptive Navigator Correction

Anja C.S. Brau¹, Yuji Iwadate², Moritz Kircher³, Shreyas Vasanawala³, Robert Herfkens³

¹Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; ²Applied Science Lab, GE Healthcare, Hino, Japan; ³Radiology, Stanford University, Palo Alto, CA, United States

Dynamic contrast-enhanced (DCE) 3D T1w MRI is routinely used in abdominal imaging for characterization of liver lesions. Each contrast-enhanced phase is typically acquired within a breath-hold; however, this multi-breath-hold requirement faces several drawbacks. In this work, navigator gating is combined with adaptive navigator correction (“slab following”) to prospectively adjust slab location based on measured motion, with the goal of improving the image quality and acquisition efficiency of navigated 3D DCE liver imaging. Initial contrast-enhanced clinical results with this method are presented.

15:30         4585.     Predicting Differentiation of Hepatocellular Carcinoma at Pre-Transplant MRI in Patients Undergoing Orthotopic Liver Transplantation

Stella K. Kang¹, Emma Robinson¹, Ramya Srinivasan¹, Bachir Taouli^1,2, Hersh Chandarana¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States; ²Radiology, Mount Sinai Medical Center, New York, NY, United States

In patients undergoing orthotopic liver transplantation, preoperative MR imaging characteristics in hepatocellular carcinoma were examined, including T1 and T2 signal intensity, diffusion weighted imaging, and dynamic contrast enhanced kinetics and their relationship with histopathologic grade was assessed.  DynaCAD, commercially available software, was utilized to examine enhancement kinetics of each tumor. Poorly differentiated HCCs had lower time to peak and higher rate of enhancement. T1 hypointensity also showed correlation with poorly differentiated tumors. No other qualitative or quantitative feature including DWI was useful in predicting HCC differentiation.

13:30         4586.     Evaluation of Uptake and Excretion of Gd-EOB-DTPA in Normal and Cirrhotic Livers

Tsutomu Tamada¹, Atsushi Higaki¹, Akihiko Kanki¹, Tomohiro Sato¹, Kazuya Yasokawa¹, Katsuyoshi Ito¹

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

We assessed differences in enhancement effects of liver parenchyma and activity of biliary and renal excretion between normal and cirrhotic livers on Gd-EOB-DTPA-enhanced MR imaging. It will be important to know that hepatic enhancement effects in the HP are decreased in patients with severe cirrhosis, probably due to impaired uptake of Gd-EOB-DTPA by hepatocytes, and biliary excretion is impaired in cirrhotic livers in comparison with normal livers while renal excretion of Gd-EOB-DPTA can be increased, probably due to the compensatory mechanism.

14:00         4587.     MR Elastography of Peritoneal Tumor

Russell Norman Low^1,2, Matthew J. Austin³, Lloyd Estkowski⁴, Richard Ehman⁵

¹Sharp and Children's MRI Center, San Diego, CA, United States; ²San Diego Imaging, San Diego, CA, United States; ³Radiology, Universit y of California at San Diego, San Diego, CA, United States; ⁴General Electric Healthcare; ⁵Mayo Clinic

We present our intial clinical experience using MR elastography in oncology patients to depict peritoneal tumor. Peritoneal tumors in the upper abdomen demonstrated increased mean shear stiffness compared to the liver as was depicted on color encoded spatial maps. On a per patient basis MRE demonstrated a .87 sensitivity, .78 specifity, and .82 accurcy. In the quantitative anlysis the mean shear stiffness of peritoneal tumor was 4.43 kPA and the mean shear stiffness of the adjancent liver was 2.36 kPa.

14:30         4588.     T2-Weighted Liver MRI at 3T Using a BLADE Technique: Comparison with a Standard Rectilinear T2-Weighted Sequence for Image Quality and Lesion Detection

Andrew B. Rosenkrantz¹, Lorenzo Mannelli¹, David Mossa¹, James Babb¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States

T2WI of the liver was performed in 28 patients at 3T using standard rectilinear and BLADE k-space trajectories.  Compared with standard T2WI, BLADE demonstrated significant improvements in in-plane motion, other ghosting artifact, liver edge sharpness, vessel sharpness, and flow suppression, a trend toward improved B1-inhomogeneity artifact, and no difference in through-plane motion.  BLADE demonstrated a significant improvement in specificity for liver lesion detection but no difference in sensitivity.  ROI analysis showed significantly improved relative contrast between the liver and focal lesions with BLADE.  We conclude that BLADE achieved significant improvements in artifacts, image quality, and specificity for liver lesion detection.

15:00         4589.     Assessment of Liver Oxygenation with BOLD MRI at 3T. Feasibility Study

Peter Beddy¹, Richard Black¹, Lorenzo Mannelli², Ilsa Joubert¹, Andrew Priest¹, David J. Lomas¹

¹Radiology, University of Cambridge and Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; ²Radiology, University of Cambridge and Addenbrookes Hospital, Cambridge,  Cambridgeshire, United Kingdom

BOLD MRI is a potential non-invasive method for assessing tissue oxygenation in a wide range of tissues.  This work develops a method for oxygen challenge based BOLD imaging of the liver at 3T in a group of volunteers and demonstrates that acceptable results and low variability can be achieved using both breath-hold and respiratory triggered multi-echo gradient echo acquisitions.

13:30         4590.     Alteration in the Conjugation Pattern of Bile Acids in Human Bile During Cholestasis: A ¹H MRS Study

Tedros Bezabeh¹, Omkar B. Ijare¹, Nils Albiin², Annika Bergquist³, Urban Arnelo⁴, Matthias Löhr³, Johannes R. Hov⁵, Ian CP Smith¹

¹National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Radiology, Karolinska Institutet, Stockholm, Sweden; ³Gastroenterology and Hepatology, Karolinska Institutet, Stockholm, Sweden; ⁴Surgery, Karolinska Institutet, Stockholm, Sweden; ⁵Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway

Conjugation of bile acids with amino acids glycine and taurine is an important phenomenon in bile formation. In healthy humans, the ratio of glycine- to taurine-conjugated bile acids is generally 3:1, and this ratio is altered in cholestatic conditions. We analyzed bile samples from patients with various cholestatic diseases and found that the median of the above ratio was 2.23:1. This alteration could be attributed to the elevation in the levels of taurine-conjugates or reduction in the levels of glycine-conjugates. Such alterations can be easily detected by ¹H MRS and the technique could be valuable in the diagnosis of diseases related to bile acid synthetic defects.

14:00         4591.     Are Dynamic First-Pass Enhancement Properties of Gadoxetic Acid (Gd-EOB-DTPA) Comparable to Gadopentetate Dimeglumine (Gd-DTPA) in Hepatocellular Carcinoma (HCC)?

Mi-Suk Park¹, Myeong-Jin Kim², Ki Whang Kim¹

¹Department of Diagnostic Radiology, Yonsei University Health System Severance Hospital, Seoul, Korea, Republic of; ²Severance hospital

In this abstract, we compared dynamic first-pass enhancement properties of gadoxetic acid with that of gadopentetate dimeglumine in the patients with HCC. Gadoxetic acid-enhanced MRI showed more rapid wash-out of HCC, stronger enhancement of hepatic parenchyma, and weaker enhancement of vessels than the standard Gd-chelate enhanced MRI.

14:30         4592.     Diffusion-Weighted Imaging: Diagnostic Value in the Assessment of Intrahepatic Metastases of Hepatocellular Carcinoma

Jeong-Sik Yu¹, Jae-Joon Chung, Joo Hee Kim, Ki Whang Kim

¹Radiology, Gangnam Severance Hospital, Seoul, Korea, Republic of

For the hepatocellular carcinomas, the presence of small satellite lesions is an important determinant of a patient¡¯s prognosis and therapeutic planning. Through the results of our study DWI is superior to dynamic MRI in the detection and characterization of subcentimeter lesions and can be added to strengthen the accuracy in the MRI assessment of intrahepatic metastases of HCCs. DWI could overcome the inherent drawbacks of dynamic MRI for the hypervascular pseudolesions or obscured tumoral vascularities by the perfusional changes in the background parenchyma serve as a complementary tool for patients examined by dynamic MRI.

15:00         4593.     Gd-EOB-DTPA Combined with Gd-DTPA: Hepatobiliary Contrast with Familiar Hepatic Dynamic Contrast Enhancement

Jesse L. Wei^1,2, Kimiknu Mentore¹, Martin P. Smith^1,2, Neil M. Rofsky^1,2

¹Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; ²Harvard Medical School, Boston, MA, United States

Administration of Gd-EOB-DTPA using the recommended dose for hepatobiliary imaging results in an unfamiliar "washed out" appearance of the liver on dynamic contrast enhanced (DCE) imaging. This likely results from increased background hepatic enhancement due to early hepatobiliary uptake.  Injection of a combination of Gd-EOB-DTPA in conjunction with an extracellular contrast agent provides the 20-minute delayed hepatobiliary phase, while preserving the familiar vascular contrast and lesion conspicuity compared to background liver on DCE images.

13:30         4594.     Flow Vector Analysis of Portal Venous Flow Using Time-SLIP (Time-Spatial Labeling Inversion Pulse) with an Optical Flow Method

Akiyoshi Yamamoto¹, Riichiro Nagashima¹, Kentaro Haraoka¹, Katsumi Nakamura¹, Mitsue Miyazaki²

¹Radiology, Tobata Kyoritsu Hospital, Kitakyushu, Fukuoka, Japan; ²Toshiba Medical Research Institute, USA, Vernon Hills, IL, United States

Flow vector analysis using optical flow can provide the useful information to assess portal venous hemodynamics enhancement using Time-SLIP.

14:00         4595.     In Vivo ¹H MRS of Gallbladder Bile Using an Optimized 8-Channel Phased Array at 3T: Towards Improved Diagnosis of Hepatopancreatobiliary Diseases

Sanaz Mohajeri^1,2, Tedros Bezabeh¹, Scott B. King¹, Omkar B. Ijare¹, Gerald Y. Minuk³, Jeremy Lipschitz⁴, Ian C.P. Smith¹

¹National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada; ³Hepatology, University of Manitoba, Winnipeg, Manitoba, Canada; ⁴Surgery, University of Manitoba, Winnipeg, Manitoba, Canada

Considering the key role of liver in body metabolism, the study of bile composition is of great importance. In vitro ¹H MRS of bile samples have shown diagnostic value in detecting various hepatopancreatobiliary disorders. Given the invasive nature of this procedure, we considered the possibility of gathering in vivo data. We present here our initial efforts to obtain bile spectra from pigs using a 3T clinical scanner comparing the use of a Siemens body array coil with an optimized home-built receive array coil.

14:30         4596.     Inhibited Hepatobiliary Excretion Is a Sign of Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis

Lena M. Hallberg¹, Annika Bergquist², Nils Albiin¹

¹Radiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden; ²Gastroenterology and Hepatology, Karolinska University Hospital, Karolinska Insitutet, Stockholm, Sweden

Cholangiocarcinoma is a well known threat to patients with primary sclerosing cholangitis (PSC). Although, early diagnosis is crucial for curative surgical treatment, it is difficult to differentiate malignant strictures from benign.  We wanted to see if excretion hepatobiliary contrast was inhibited in affected segments, as a sign of malignancy. Therefore, six patients with PSC and a histopathologically confirmed cholangiocarcinoma , were examined in a 1.5 T MRI and Gd-BOPTA i.v. administered. In five of these patients there was no sign of excretion in affected segments. Thus, inhibited hepatobiliary excretion is a sign of cholangiocarcinoma in patients with primary sclerosing cholangitis.

15:00         4597.     Gd-EOB-DTPA Enhanced MR Imaging: Evaluation of Enhancement Effects and Enhancement Patterns in Hepatic Hemangioma

Tsutomu Tamada¹, Atsushi Higaki¹, Akihiko Kanki¹, Satoko Okamoto¹, Katsiyoshi Ito¹

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

We assessed quantitatively and qualitatively the enhancement effects and the enhancement patterns of hepatic hemangioma and normal liver tissue on Gd-EOB-DTPA-enhanced MR imaging. It will be important to know that the dynamic enhancement pattern of hepatic hemangioma is similar to that of hepatocellular carcinoma, probably due to the washout of Gd-EOB-DTPA in the early stage after contrast media administration compared with extracellular Gd chelates.

Lung MRI

14:00         4598.     First Results from Clinical Sitings of a High Production Prototype Xenon Polarizer

F. William Hersman^1,2, Jeff Ketel², Iulian Constantin Ruset, ^1,2, Stephen Ketel², Isabel Dregely¹, Walter Porter², David W. Watt², John P. Mugler, III³, Talissa A. Altes³, Kai Ruppert³, Jaime F. Mata³, Samuel Patz⁴, Hiroto Hatabu⁴, Mirko Hrovat⁵, Iga Muradian⁴, Mikayel Dabaghyan⁴, G. Wilson Miller³, Chengbo Wang³, James P. Butler⁶, Jan H. Distelbrink²

¹University of New Hampshire, Durham, NH, United States; ²Xemed LLC, Durham, NH, United States; ³University of Virginia, Charlottesville, VA, United States; ⁴Brigham and Women's Hospital, Boston, MA, United States; ⁵Mirtech, Inc, Brockton, MA, United States; ⁶Harvard School of Public Health, Boston, MA, United States

Hyperpolarized xenon-129 is potentially the most viable contrast agent to be used for characterizing pulmonary function by MRI. Further improvements in polarizing technology yield production rates of up to 15 liters/hour with 50% polarization. This high production prototype polarizer was relocated to two clinical sites and demonstrated in pilot clinical studies. First fully engineered systems based on this design, XeBox-E10, will be available in 2010 for collaborative research.

14:30         4599.     Producing Hyperpolarized Gases Via Dynamic Nuclear Polarization and Sublimation

Arnaud Comment^1,2, Sami Jannin³, Jean-Noël Hyacinthe⁴, Pascal Miéville³, Riddhiman Sarkar³, Puneet Ahuja³, Paul Romeo Vasos³, Xavier Montet⁴, François Lazeyras⁴, Jean-Paul Vallée⁴, Joseph A. Konter⁵, Patrick Hautle⁵, Ben van den Brandt⁵, Jean-Philippe Ansermet², Rolf Gruetter^1,6, Geoffrey Bodenhausen^3,7

¹Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ²Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ³Laboratory of Biomolecular Magnetic Resonance, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ⁴Department of Radiology, Université de Genève, Genève, Switzerland; ⁵Paul Scherrer Institute, Villigen, Switzerland; ⁶Departments of Radiology, Universités de Lausanne et Genève, Lausanne and Genève, Switzerland; ⁷Department of Chemistry, Ecole Normale Supérieure, Paris, France

A method to produce hyperpolarized gases by dynamic nuclear polarization and subsequent sublimation was designed. The method was illustrated by applications to ¹²⁹Xe in xenon gas, leading to the enhancement of the nuclear magnetic resonance signal-to-noise by four orders of magnitude. The main advantage of this new hyperpolarization method lies in its ability to produce highly polarized gases with large throughputs, on the order of tens of several liters per hour.

15:00         4600.     A Dedicated Coil Configuration for Hyperpolarized 129Xe Imaging at 1.5 T

Armin Purea¹, Kevin Teh², Michael Barlow², Dominik Berthel¹, Alexander Weisser¹, Ian Hall³, Peter Morris²

¹Rapid Biomedical GmbH, Rimpar, Germany; ²Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom; ³IPSET, University of Nottingham, Nottingham, United Kingdom

Presented are preliminary results from a novel coil configuration for 129Xe lung imaging.  A non-circular birdcage was used as a transmit coil and a 8 channel receive coil were proposed. The coils were designed to utilise the bore space as much as possible to enhance patient comfort whilst not compromising the image quality. Initial images obtained using a SPGR sequence shows great promise. Scan time for lung patients will potentially decrease with the use of parallel receivers which were designed for optimum signal as much as flexibility.

15:30         4601.     3D Hyperpolarized 3He Imaging of Human Lung with Isotropic Spatial Resolution Using 3D-Cones

Jian-Xiong Wang¹, Alexei V. Ouriadov², Jeffrey A. Stainsby³, Grace E. Parraga², Giles Santyr^2,4

¹Applied Science Laboratory, GE HEALTHCARE, London, ON, Canada; ²Robarts Research Institute, The University of Western Ontario, London, ON, Canada; ³Applied Science Laboratory, GE HEALTHCARE, Toronto, ON, Canada; ⁴Dept. of Medical Biophysics, The University of Western Ontario, London, ON, Canada

A true 3D isotropic spatial resolution imaging method for Hyperpolarized He-3 human lung imaging using 3D-cones sequence is presented. The isotropic voxel size improves accuracy for co-registration, lung volume measurement and analysis for abnormalities in the lung.

13:30         4602.     Evaluation of Global Surface-To-Volume Ratio of Rabbit Lung Using Hyperpolarized 129Xe Uptake Spectroscopy at 1.5T

Yulin Chang¹, Jaime F. Mata¹, Talissa Altes¹, John P. Mugler III¹, Kai Ruppert¹

¹Radiology, University of Virginia, Charlottesville, VA, United States

Hyperpolarized xenon-129 dissolves into lung tissue and binds hemoglobin and the dissolved-phase (DP) xenon molecules exchange with the gas-phase molecules via diffusion. Therefore the initial rate of the signal replenishment of the DP xenon following a saturation is proportional to both square root of time and lung surface area. In this work we demonstrate the possibility of measuring lung surface-to-volume ratio using DP xenon signals at short delays after a complete saturation in a rabbit model.

14:00         4603.     Long-Range Diffusion of Hyperpolarized 3He in Normal and Emphysematous Rat Lungs

Ignacio Rodriguez^1,2, Laura Carrero-Gonzalez, ^1,3, Thomas Kaulisch³, Detlef Stiller³, Jose Manuel Perez-Sanchez⁴, Jesus Ruiz-Cabello^1,2

¹Instituto de Estudios Biofuncionales, Universidad Complutense, Madrid, Spain; ²CIBER de Enfermedades Respiratorias, Madrid, Spain; ³Boehringer Ingelheim Pharma, Biberach an der Riss, Germany; ⁴Univ. Paris-Sud, CNRS, Orsay, France

Using long-range diffusion MRI, ADC of rats with induced emphysema in one lobe has been performed. The results show a statistically significant increase of ADC in the emphysematous lobe at breath-hold, whereas no significant difference is seen at end expiration. Collateral ventilation could play a role in these results. The increase seen at breath-hold agrees with the results found by other workers.

14:30         4604.     Comprehensive Pulmonary Evaluation of Emphysematous Mice Using Hyperpolarized ¹²⁹Xe MRI/MRS Under Spontaneous Breathing Mode

Hirohiko Imai^1,2, Atsuomi Kimura², Takuya Kitao², Emi Okubo², Yuki Hori², Satoshi Iguchi², Hideaki Fujiwara²

¹Center for Advanced Research and Education in Drug Discovery and Development, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan; ²Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan

Several techniques in hyperpolarized ¹²⁹Xe MRI and MRS were applied to spontaneously breathing mice for comprehensively evaluating pulmonary structures and functions in emphysematous mice. The abnormalities of pulmonary structure, perfusion and ventilation were successfully detected in emphysematous mice, while significant difference was not shown in gas exchange. Although further improvement was needed for evaluating gas exchange in spontaneous breathing condition, it was shown that the method described here could become useful for drug research and development using small rodents since this protocol was able to detect several important pathological changes non-invasively.

15:00         4605.     Hyperpolarized ³He ADC Measurements: Left-Right and Dorsal-Ventral Differences as a Function of Lung Volume

Ahmed F. Halaweish¹, Daniel R. Thedens¹, Jered P. Sieren¹, Eric A. Hoffman¹, Edwin J.R. vanBeek¹

¹University of Iowa, Iowa City, IA, United States

Hyperpolarized ³Helium MRI Apparent Diffusion Coefficient (ADC) measurements enable probing of the lung microstructure and evaluation of pathological processes that affect airspace size. We successfully evaluated ADC measurements as a function of lung volume in 12 never-smoker subjects across three different lung volumes (20%, 60% & 100%VC). Significant differences between each lung volume were observed, along with significant ventral-dorsal gradients at the 20%VC volume and a more homogenous left-right distribution at 100%VC only. Results suggest that patterns of ADC throughout the lungs in the never-smoker subjects follow proper distribution and ventilation patterns and emphasize the importance of controlled lung inflation.

13:30         4606.     Dynamic O2-Enhanced MRI Vs. Quantitative Thin-Section MDCT: Capability for COPD Assessment in Smokers - not available

Yoshiharu Ohno^1,2, Hisanobu Koyama¹, Keiko Matsumoto^1,3, Yumiko Onishi¹, Daisuke Takenaka¹, Munebu Nogami¹, Nobukazu Aoyama², Hideaki Kawamitsu², Makoto Obara⁴, Marc van Cauteren⁴, Kazuro Sugimura¹

¹Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; ²Radiology, Kobe University Hospital, Kobe, Hyogo, Japan; ³Radiology, Yamanashi University, Shimokatou, Yamanashi, Japan; ⁴Philips Healthcare, Tokyo, Japan

Direct assessment of signal intensity - time course curve on dynamic O2-enhanced MRI have suggested as having potential for airway abnormality and oxygen transfer assessments.  However, the literature shows no publications dealing with direct comparison of the capability of quantitatively assessed thin-section MDCT and of dynamic O2-enhanced MRI for COPD assessment in smokers.  We hypothesized that dynamic O2-enhanced MRI may have potential for COPD assessment, and be considered at least as valuable as MDCT in smokers.  The purpose of this study was to compare the capability for COPD assessment in smokers between dynamic O2-enhanced MRI and quantitatively assessed thin-section MDCT.

14:00         4607.     Oxygen-Enhanced MRI in Patients with Pulmonary Arterial Hypertension: Feasibility and Value

Daniel Maxien¹, Olaf Dietrich², Sven Thieme², Maximilian Reiser², Konstantin Nikolaou²

¹Department of Clinical Radiology, Ludwig Maximilian University, Munich, Germany; ²Department of Clinical Radiology, Ludwig Maximilian University Munich, Germany

Oxygen-enhanced MRI of the lung has proved its feasibility in studies with healthy volunteers, but till now there is only limited experience in circumscribed patient cohorts. We wanted to determine the value and feasibility of oxygen-enhanced MRI in patients with pulmonary arterial hypertension. Therefore we evaluated the sensitivity and specificity of oxygen-enhanced MRI versus ventilation and perfusion scintigraphy.  Furthermore, we made a quantitative comparison of the relative signal enhancement in defect areas with the relative signal enhancement in the whole lung to determine which signal difference is needed for a reliable visual detection of diseased lung areas.

14:30         4608.     Improvement of Multislice Oxygen-Enhanced MRI of the Lung by Fully Automatic Non-Rigid Image Registration.

Francesco Molinari^1,2, Grzegorz Bauman³, Monika Eichinger², Bernhard Geiger⁴, Lorenzo Bonomo¹, Hans-Ulrich Kauczor⁵, Michael Puderbach²

¹Department of Bioimaging and Radiological Sciences, Catholic University of Rome, Rome, Italy; ²Department of Radiology, German Cancer Research Center, Heidelberg, Germany; ³Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; ⁴Siemens Corporate Research, Princeton, United States; ⁵Department of Radiology, University of Heidelberg, Heidelberg, Germany

In oxygen-enhanced MRI, lung signal is measured repeatedly during different breathing cycles. Inconsistencies of respiratory phase may hamper the quality of the parametric O2-maps. In this study, fully automatic non-rigid registration was assessed as a postprocessing method to improve the quality of O2-MRI of the lung. This post-processing technique reduced spatial misalignment among images and signal variability within the lung. O2-induced signal enhancement was not influenced by image registration. Spatial heterogeneity of parametric O2-maps decreased significantly. As such, fully automatic non-rigid registration appears suitable for improving the quality of multislice O2-MRI of the lung.

15:00         4609.     Ultra-Short Echo Time (UTE) MR Imaging of the Lung: Assessment of Tissue Density in the Lung Parenchyma

Masaya Takahashi¹, Osamu Togao¹, Riki Tsuji¹, Ivan Dimitrov¹

¹Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States

The utility of ultra-short TE (UTE) imaging in conjunction with projection acquisition of the free induction decay helps to acquire the MR signal from the lung parenchyma. We applied an UTE sequence for imaging of the murine lung at different positive end-expiratory pressures (PEEP) in a 3 T clinical MRI system. The signal intensity and T2* of the lung parenchyma measured with a UTE sequence reduced as the PEEP became higher where the lung volume increased.  We found that both are highly correlated with the lung volume.

13:30         4610.     Automated Airway Lumen Segmentation and Characterization for Use in Patients with Traqueomalacya: A Feasibility Study

Piotr Alfred Wielopolski¹, Pierluigi Ciet², Gabriel Paul Krestin¹, Martin H. Lequin¹, Harm Tiddens³, Rashindra Manniesing⁴

¹Radiology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands; ²Department of Medical-Diagnostic Sciences and Therapies, Policlinico Universitario di Padova, Padova, Italy; ³Department of Pulmonology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands; ⁴Department of Informatics and Radiology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands

The purpose of this work was to provide: first, a suitable acquisition scenario including static and dynamic 3D MRI sequences with sufficient temporal and spatial resolution to provide good morphological information and visualization of dynamic events in the central airways and, secondly, to provide the means for an automatic analysis program suitable to segment the airway lumen and a dynamic evaluation of cross-sectional areas of the central airways down to the 2nd generation branching.

14:00         4611.     MRI Assessment of Dynamic Lung Volume Changes in Subjects Using a Nasal Expiratory Positive Airway Pressure (NEPAP) Device - not available

Ding Xia¹, Elan J. Grossman¹, D M. Rapoport², I Ayappa², A V. Patel², L Daugherty³, Jian Xu¹, Kelly Anne Mcgorty¹, Qun Chen¹

¹Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; ²Division of Pulmonary and Critical Care Medicine, NYU School of Medicine, New York, United States; ³Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

The purpose of the current study is to use a real-time MRI technique for measuring lung volume changes caused by using a nasal expiratory positive airway pressure (nEPAP) device, a new treatment for obstructive sleep apnea (OSA). This may help us better understand the mechanism by which it treats OSA. Our results show there is an increase in functional reserve capacity (FRC) while using the nEPAP device. Since end-expiratory hyperinflation is likely to produce increased traction in the trachea, this suggests the main action of the nasal expiratory device may be to stiffen the upper airway through increased longitudinal traction.

14:30         4612.     MRI Assessment of Distal Airway Heterogeneity for the Early Detection of Airway Disease with Normal Spirometry

Ding Xia¹, Elan J. Grossman¹, Ke Zhang¹, Abram Voorhees², K I. Berger³, R M. Goldring³, B W. Oppenheimer³, J Reibman³, W N. Rom³, L Rogers³, A Helwig³, L Daugherty⁴, Jian Xu¹, Kelly A. Mcgorty¹, Qun Chen¹

¹Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; ²Siemens Medical Solutions, Malvern, PA, United States; ³Department of Medicine, NYU School of Medicine, New York, United States; ⁴Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

Clinical-pathologic correlation between patient illness and pulmonary disease is difficult to determine when airway abnormalities are localized only to distal airways of the lungs. The purpose of this study is to establish quantitative regional measurements of heterogeneity for distal airway dysfunction based on a tissue tracking MRI technique and apply them to early diagnosis of obstructive airway disease. Results show that in subjects with suspected distal airway disease MRI indicators of mean regional airflow are reduced despite presentation of normal spirometry. Thus, assessment of regional lung function by MRI may be a useful tool for early detection of airway disease.

15:00         4613.     Sensitivity of Viscosity and Elasticity in Preserved Pig Lung by Magnetic Resonance Elastography

Roberta Santarelli¹, Xavier Maître¹, Ralph Sinkus², Luc Darrasse¹

¹Imagerie par Résonance Magnétique et MultiModalités (UMR8081), Univ Paris-Sud, CNRS, Orsay, France; ²Institut Langevin (UMR 7587), ESPCI, Univ Denis Diderot, CNRS, Paris, France

Viscoelastic properties of lungs participate in the organ basic function. Their exploration in vivo is not attainable. Hyperpolarised helium-3 MR-elastography on lungs has been demonstrated in vivo. This new technique ex vivo quantitatively evaluated the comparison between helium-3 and hydrogen MRE: the fluid/structure coupling was found to be strong, validating helium-3 lung MRE as a consistent tool for lung exploration. This work focuses on viscoelastic properties behaviour of hydrogen MRE, applied on the preserved pig lung inflated at different volumes: performance of wavelength, elasticity, and viscosity distribution is discernible throughout the inner area and the outer peripheries of the lungs

Obesity & Metabolism

14:00         4614.     Abdominal Adipose Tissue Distribution: Regional Differences

Min-Hui Cui¹, Jong Hee Hwang¹, Vlad Tomuta¹, Daniel T. Stein¹

¹Albert Einstein College of Medicine, Bronx, NY, United States

Fifty-eight non-diabetic subjects with a wide range of BMI were studied to evaluate the regional differences of SAT and VAT distribution and the correlations of them with intrahepatic lipid, plasma triglyceride, glucose and FFA levels. Both lean and overweight/obese subjects have most SAT in lower abdomen. However, lean subjects have more VAT while overweight/obese subjects have less VAT in lower abdomen. The relationships between SAT and VAT from different abdominal regions in the lean and overweight/obese subjects with IHL, TG and glucose are also different. Thus conclusions based on one specific AT region should be interpreted with cautions.

14:30         4615.     Whole Body Fat Water Imaging at 3 Tesla Using Multi-Echo Gradient Echo

E. Brian Welch^1,2, Johan Berglund³, Heidi J. Silver⁴, Kevin D. Niswender⁵, Morten Bruvold⁶, Joel Kullberg³, Lars Johansson³, Malcolm J. Avison¹

¹Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States; ²MR Clinical Science, Philips Healthcare, Highland Heights, OH, United States; ³Department of Radiology, Uppsala University, Uppsala, Sweden; ⁴Vanderbilt Center for Human Nutrition, Vanderbilt University Medical Center, Nashville, TN, United States; ⁵Vanderbilt Diabetes Research and Training Center, Vanderbilt University Medical Center, Nashville, TN, United States; ⁶MR Clinical Science, Philips Healthcare, Best, Netherlands

The potential of whole body MRI for visualizing adipose tissue distribution has long been recognized. More recently, multi-gradient-echo MR acquisitions have been successfully used at 1.5 Tesla to quickly acquire whole-body data sets. Automated segmentation and quantification of such whole-body fat images into subcutaneous and visceral adipose tissue compartments shows great promise as a tool in studies of obesity and other metabolic syndrome diseases such as diabetes. Most whole-body fat-water imaging has been performed at 1.5 Tesla. However, the availability and prevalence of higher strength 3 Tesla scanners, especially in research settings, justifies the pursuit of robust multi-gradient-echo sequences designed to operate at 3 Tesla. Here we present initial results of a 3T multi-gradient echo whole-body fat-water sequence.

15:00         4616.     Rapid, Multi-Slice Fat Water Separated Imaging for Mapping Body Fat

Peter Kellman¹, Diego Hernando², Saurabh Shah³, Z-P Liang², David A. Bluemke¹, Andrew E. Arai¹

¹National Institutes of Health, Bethesda, MD, United States; ²University of Illinois, Urbana, IL, United States; ³Siemens Medical Solutions, Chicago, IL, United States

A rapid multi-slice fat/water separated imaging protocol has been developed for mapping body fat with application to obesity studies. The method combines a 3-echo GRE acquisition and parallel imaging to scan the abdomen and chest in <30 sec. A recently developed joint estimation method for water/fat separation is able to perform robustly in the presence of large B0 field inhomogeneities.

15:30         4617.     Automated Quantification of Adipose Tissue Distribution in Children Using a 2-Point Dixon Technique

Joel Kullberg¹, Pär-Arne Svensson², Ann-Katrine Karlsson^3,4, Eira Stokland², Jovanna Dahlgren^3,4

¹Department of Radiology, Uppsala University, Uppsala,  N/A, Sweden; ²Department of Pediatric Radiology, The Sahlgrenska University Hospital, Göteborg, Sweden; ³Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden; ⁴The Queen Silvia Children's Hospital, Göteborg, Sweden

A method for assessment of adipose tissue distribution in children is presented. The method utilizes rapid water-fat imaging of 16 slices of the abdomen. A fully automated segmentation algorithm for assessment of visceral and subcutaneous adipose tissue volumes is described. The automatically measured results from 21 volunteer 5-year-olds are compared to those from semi-automated segmentation. Acceptable results were achieved despite the children’s young age and the relatively small adipose tissue volumes measured.

13:30         4618.     Alterations on Hepatic Glycogen and Lipid Metabolism Following the Induction of Diabetes in the Rat

Ana Francisca Soares^1,2, John Griffith Jones¹, Francisco Veiga², Rui Albuquerque Carvalho¹

¹Life Sciences, Faculty of Sciences and Technology and Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal; ²Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal

The liver stores carbohydrate and lipid after a meal under insulin stimulation. Using deuterated water, we assessed hepatic glycogen synthesis and de novo lipogenesis in healthy and streptozotocin-induced diabetic rats feeding overnight. Hepatic glycogen and lipid content were analyzed by 2H-NMR. Healthy animals showed similar direct and indirect pathway contributions to glycogen. Following Diabetes induction we observed a progressive loss of direct pathway capacity compared to the indirect and also a reduction of de novo lipogenesis. These observations may serve as valuable markers for assessing alterations in hepatic glucose and lipid metabolism during the progress Diabetes.

14:00         4619.     In Vivo Monitoring of Treatment Effect of Cryptotanshinone for Non-Alcoholic Fatty Liver Disease in Mice - not available

Hyeon Seung Lee¹, Quan Yu Cai¹, Ki Nam Min², Jong Kook Park², Tae Hwan Kwak², Kyeong Hoon Jeong², Kwan Soo Hong¹

¹MRI, Korea Basic Science Institute, Ochan-Eub, Chungcheonbuk-Do, Korea, Republic of; ²Advanced Biological Research, Mazence Inc, Suwon, Gyeonggi-Do, Korea, Republic of

Treatment of Non-Alcoholic Fatty Liver by Cryptotanshinone in Mouse Models for Hepatic Steatosis

14:30         4620.     Functional Magnetic Resonance Imaging of Liver:  Effect of Glucose - not available

muhammad E. Haque¹, Ioannis Koktzoglou¹, Wei Li¹, Jo Ann Carbray¹, Pottumarthi V. Prasad¹

¹Radiology, North Shore University Healthcare System, Evanston, IL, United States

One of the primary functions of insulin is disposal of glucose from the blood and inhibition of hepatic glucose production (HGP).  Dysfunction of either of these processes can cause development of type II diabetes. Incomplete suppression of HGP is a strong indication of insulin resistance and may be an early marker for development of type II diabetes. Current methods to evaluate insulin resistance are complicated, invasive and hence not used in routine practice. Here we demonstrate feasibility of using BOLD MRI to monitor oxygenation changes in the liver following glucose which may be related to insulin sensitivity.

15:00         4621.     Two Site Water Exchange Analysis of Pancreatic T1 Relaxation Reveals the Kinetics and Mechanism of Beta Cell Labeling with Manganese: Implications for Imaging Beta Cell Mass in Diabetes

Patrick Antkowiak¹, Moriel Vandsburger, Frederick Epstein

¹University of Virginia, Charlottesville, VA, United States

The kinetics and mechanism of pancreatic β cell labeling with Mn2+ were investigated. Murine pancreatic T1 relaxation was measured in normals and after treatment with the Ca2+ channel blocker nifedipine. Two site water exchange analysis of pancreatic T1 relaxation provided the intracellular T1 and intracellular fraction, measures of β cell labeling. Increased intracellular T1 and lower intracellular fraction in nifedipine-treated mice confirmed Mn2+ enters β cells through Ca2+ channels. The timecourse of intracellular T1 and fraction in normal mice revealed 3 phases of Mn2+ kinetics: 1) labeling β cells, 2). washout from β cells, 3). nonspecific labeling of other cells.

Lung MRI

13:30         4622.     Dynamic Contrast Enhanced Pulmonary Perfusion with Undersampled Stack-Of-Stars and Iterative Highly Constrained Back-Projection

Nathan S. Artz¹, Rafael L. O'Halloran², Mark Schiebler³, James H. Holmes⁴, Sean B. Fain^1,3

¹Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; ²Radiology, Stanford University, Stanford, CA, United States; ³Radiology, University of Wisconsin-Madison, Madison, WI, United States; ⁴Applied Science Laboratory, GE Healthcare, Madison, WI, United States

Pulmonary perfusion was assessed in two healthy volunteers using a contrast-enhanced 3D stack-of-stars GRE sequence.  Consecutive groups of 32 projection angles were reconstructed with IHYPR for a temporal resolution of ~1s.  The signal vs. time curves demonstrate an expected trend with the pulmonary artery peaking first, followed next by the parenchyma and later the left atrium.  Mean transit time, relative pulmonary blood volume and relative pulmonary blood flow maps demonstrate expected results with mean transit times from 3-5 s after the main pulmonary artery trunk and shorter MTT’s in the posterior region due to gravity related effects.

14:00         4623.     Comparison of Three Quantification Algorithms (RFM, TSVD, LCC) for Absolute Quantification of Pulmonary Perfusion in Patients with COPD and Pulmonary Embolism by MRI

Mona Salehi Ravesh¹, Michael Puderbach², Sebastian Ley³, Julia Ley-Zaporzhan³, Frank Risse¹, Wilfried Schranz⁴, Wolfhard Semmler¹, Frederik Bernd Laun¹

¹Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; ²Department of Radiology, German Cancer Research Center, Heidelberg, Germany; ³Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany; ⁴Nonlinear Physics Group, Faculty of Physics, University of Vienna, Vienna, Austria

Lung perfusion is a crucial prerequisite for effective gas exchange. An accurate quantification of pulmonary perfusion is therefore important for diagnostic considerations and treatment planning in various diseases of the lungs.The assessment of pulmonary perfusion by Dynamic Contrast-Enhanced Magnetic Resonance Imaging requires deconvolution of the arterial input function. In the presence of noise this is an ill-posed problem which leads to strongly oscillating, unphysical solutions when it is solved without regularization. In this study a novel method to quantify the pulmonary perfusion is used and compared to the singular value decomposition and L-curve criterion based on simulated and patient data.

14:30         4624.     Bronchial Perfusion in the Lungs Observed by Dynamic Contrast-Enhanced MRI

Nabil Saouti¹, Anton Vonk Noordegraaf¹, Michael Ingrisch², J. Tim Marcus¹

¹VU University Medical Center, Amsterdam, Netherlands; ²Ludwig-Maximilian University, Munich, Germany

The aim is to visualise the perfusion of the lungs by the pulmonary and bronchial system separately, based on the fact that a contrast bolus injected intravenously will arrive later in the bronchial than in the pulmonary system. Included were 7 patients with whole left or right pulmonary artery atresia, and 6 chronic thromboembolic pulmonary hypertension patients. Using 3D dynamic contrast-enhanced MRI with 1 s temporal resolution, a 5 s signal-intensity onset delay was measured between open lung or lung region, and obstructed lung (region), providing evidence for bronchial arterial supply after a pulmonary artery obstruction.

15:00         4625.     Ventilation/Perfusion MR Imaging of the Lung Using T1-Weighted Ultra-Short Echo Time (UTE) Imaging: Animal Experiment in a 3 T Clinical MRI System

Osamu Togao¹, Marc van Cauteren², Yoshiharu Ohno³, Ivan Dimitrov^1,2, Masaya Takahashi¹

¹Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; ²MR Clinical Science, Philips Healthcare, Best, Netherlands; ³Radiology, Kobe University Graduate School of Medicine, Kobe , Hyogo, Japan

We have demonstrated that an UTE sequence could bring inherent MR signal of the lung parenchyma that closely related to the parenchymal tissue anatomy. We hypothesize that the capability of the method to acquire inherent MR signal of the lung parenchyma should allow us to assess changes in SI due to inhalation of molecular oxygen or intravenous injection of gadolinium. In the present study, we tested the feasibility of a T1-weighted UTE sequence for assessment of regional pulmonary ventilation/perfusion which is essential for the evaluation of a variety of lung diseases in a 3T clinical MRI system.

13:30         4626.     Self-Referenced Flip Angle Mapping for Hyperpolarized Gas MRI

Eric Frederick^1,2, Mirko Hrovat³, Samuel Patz²

¹Applied Physics, University of Massachusetts in Lowell, Lowell, MA, United States; ²Radiology, Brigham and Women's Hospital, Boston, MA, United States; ³Mirtech Inc, Brockton, MA, United States

Hyperpolarized noble gas imaging is a non-equilibrium imaging method where gas magnetization is depleted by RF excitations. Due to B_1 field inhomogeneities, this depolarization may not be uniform and therefore a B_1 flip angle map is required to correct the images. This process is typically performed by acquiring an additional set of images. We propose an alternative method where the flip angle map is obtained from one set of images. To do this, we break up a fully sampled image into two undersampled images that are then used for B_1 flip angle mapping. We demonstrate these methods with simulations.

14:00         4627.     Towards a Better Understanding of Helium-3 MRI Manual Segmentation Error Using Fuzzy C-Mean Methods

Mohammadreza Heydarian¹, Andrew Wheatley¹, Grace Parraga^1,2

¹Robarts research Institute, London, Ontario, Canada; ²Medical Biophysics, University of Western Ontario, London, On, Canada

Hyperpolarized helium-3 MRI provides a way to visualize and quantify lung function based on segmentation of helium-3 ventilation images. Manual segmentation of 3He ventilation volumes is time consuming and prone to observer error. To address this limitation, we developed and applied a fully automated fuzzy c-mean (FCM) method for segmenting ventilated regions and observed significant associations between the automated and manual segmentation methods. FCM provides a fully automated, robust and efficient method for segmenting ventilated regions of hyperpolarized helium-3 images.

14:30         4628.     Optimisation of Velocity Encoding Gradients for Phase Contrast Gas Velocity Taking Diffusion Into Account.

Lionel Martin¹, Xavier Maître¹, Mathieu Sarracanie¹, Marlies Friese², Ludovic de Rochefort¹, Rose-Marie Dubuisson¹, Emeline Boriasse¹, Emmanuel Durand¹

¹Imagerie par Résonance Magnétique Médicale et MultiModalités (UMR8081), Univ Paris-Sud, CNRS, Orsay, France; ²Center for Magnetic Resonance, The University of Queensland, Brisbane, Queensland, Australia

MR flow measurement techniques have mostly been used in liquids. For coherent motion (flow), bipolar gradients induce a phase shift and a signal drop for incoherent motion (diffusion). This effect, negligible for liquids, cannot be neglected for gases. Competition between these two phenomena results in the existence of an optimal FOS that could be theoretically determined. 2D velocity maps of parabolic flows were acquired with different FOS and gases. Results show that velocity error is a function of the FOS and a different optimal FOS is reached for each gas. Thus, they validate our theoretical simulations.

15:00         4629.     Hyperpolarized 83Kr MR Relaxation Measurements in Excised Rat Lungs.

Karl F. Stupic¹, Nancy D. Elkins², Galina E. Pavlovskaya³, John E. Repine², Thomas Meersmann, ^1,3

¹Department of Chemistry, Colorado State University, Fort Collins, CO, United States; ²Health Science Center, Webb-Waring Institute, University of Colorado, Denver, CO, United States; ³School of Medicine, University of Nottingham, Nottingham, United Kingdom

Hyperpolarized (hp) 83Kr has been previously shown to provide T1 relaxation weighted MRI contrast that is highly sensitive to the surface chemistry in low surface-to-volume model surface systems In the present work 83Kr T1 relaxation in excised rat lungs is investigated as a function of lung inflation. Surprisingly, the relaxation in ex vivo lungs does not change with increased lung inflation (when the effects of airways are eliminated) despite the presumably changing surface to volume ratios in the alveoli. The measured relaxation times are long enough to permit future in vivo studies.

Metabolism Liver & Other I

14:00         4630.     Reproducibility of MRI-Determined Proton Density Fat Fraction (PDFF) Across MR Scanner Platforms and Field Strength

Geraldine Hye Won Kang¹, Michael Schroeder¹, Masoud Shiehmorteza¹, Benjamin Johnson¹, Tanya Wolfson¹, Anthony Gamst¹, Gavin Hamilton¹, Mark Bydder¹, Takeshi Yokoo¹, Claude Sirlin¹

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

As a result of the growing epidemic of obesity, fatty liver disease has become the most common liver condition in the United States. Thus, there is an increasing need for a noninvasive fat quantification technique. We have developed a T1-independent, T2*-corrected, spectral modeled chemical shift based fat quantification technique, which permits estimation of the proton density fat fraction (PDFF). Here we show that PDFF measured by this technique is reproducible across field strength and vendor and has high accurt5acy using spectroscopy as the reference.

14:30         4631.     Association of Obesity with Fatty Infiltration of the Pancreas Diagnosed at MRI

Ely Felker¹, Lorenzo Mannelli¹, Emilio Vega¹, Michael Bloom¹, Hersh Chandarana¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States

In addition to being associated with several metabolic disturbances, such as insulin resistance and diabetes mellitus, obesity causes fat infiltration of several organs, including the heart, liver, and skeletal muscle.  The purpose of this study was to characterize the relationship between pancreatic fat infiltration and known markers of obesity.  We showed that pancreatic fatty infiltration at MRI was significantly related to central fat volume, peripheral fat volume, and body mass index.  Further study will enhance understanding of mechanisms that link obesity to its metabolic complications as well as, perhaps, provide an early marker for incipient insulin resistance and metabolic syndrome.

15:00         4632.     Non Alcoholic Fatty Liver Disease (NAFLD) and Visceral Fat: Accurate Spectroscopic and Volumetric Determinations Derived from MR

Khalil N. Salman¹, Puneet Sharma², Bobby Kalb¹, Hiroumi Kitajima², Christina Lurie¹, Miriam Vos³, Diego R. Martin¹

¹Radiology, Emory University, Atlanta, GA, United States; ²Radiology, Emory Healthcare, Atlanta, GA, United States; ³Pediatrics, CHOA, Atlanta, GA, United States

Non Alcoholic Fatty Liver disease(NAFLD) has become a serious problem in the USA. biopsy procedures are invasive and pose a high risk of morbidity. MRS of the liver along with volumetric visceral and subcutaneous fat measurement have shown to be an independent measure of fatty liver. This study investigates the correlation between volumetric fat measurements and hepatic fat fraction using HISTO technique.

15:30         4633.     Estimation of the Prevalence of Liver Fibrosis in Patients Receiving Chronic Methotrexate Therapy with MR Elastography

Jun Chen¹, Deana Hoganson², Meng Yin¹, Kevin Glaser¹, Jayant Talwalkar³, Eric Matteson², Richard Ehman¹

¹Department of Radiology, Mayo Clinic, Rochester, MN, United States; ²Division of Rheumatology, Mayo Clinic, Rochester, MN, United States; ³Division of Gastroenterology, Mayo Clinic, Rochester, MN, United States

Methotrexate (MTX) has become the most frequently prescribed disease modifying antirheumatic agent (DMARD) for rheumatoid arthritis (RA), due to its efficacy, low cost and tolerability. An ongoing primary concern of MTX treatment is its potential hepatotoxicity. Guidelines published in 1994 by the American College of Rheumatology (ACR) suggest that serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and albumin be monitored every 4-8 weeks for assessing hepatotoxicity in RA patients receiving MTX. If a patient develops 5 of 9 abnormal AST values within a 12 month time frame or if serum albumin decreases below the normal range, a liver biopsy is recommended. Because of the apparently low rate of clinically significance, MTX related hepatotoxicity, the usefulness and cost-effectiveness of such frequent monitoring, particularly in the absence of risk factors for liver disease have been brought into question. The unavailability of accurate non-invasive hepatic fibrosis detection methods other than biopsy has frustrated clinicians in addressing these important questions. Since its advent 15 years ago [8], Magnetic Resonance Elastography (MRE) has developed into a clinical useful diagnostic technology. This abstract reports interim results from a currently ongoing project using MRE to assess hepatic fibrosis in RA patients who are on MTX treatment seen at our institution.

13:30         4634.     Comparison of MR Elastography and DWI for Assessment of Hepatic Fibrosis

James F. Glockner¹, Christine U. Lee¹, Richard L. Ehman¹

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

Hepatic MR elastography and DWI with low and intermediate b-values were performed in 29 patients with suspected chronic liver disease.  ADC measurements for both b-values demonstrated a negative correlation with hepatic stiffness as determined by MRE.  The range of variation of in stiffness values is larger than that of ADC values, suggesting that MRE may be more sensitive to small variations in hepatic stiffness.

14:00         4635.     R2* as a Surrogate Measure of Ferriscan® Iron Quantification in Thalassemia

Wesley Calvin Chan¹, Faisel Budhani¹, Zahra Tejani¹, Christine Massey², Masoom A. Haider¹

¹Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada; ²Dalla Lana School of Public Health, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, ON, Canada

Monitoring hepatic iron concentration is an important clinical concern in thalassemia patients. The aim of this study is to demonstrate a correlation between R2* relaxation rate and liver iron concentration determined by the FDA approved Ferriscan® method.  We found a very strong linear correlation between R2* values and Ferriscan® determined liver iron concentration with the Spearman correlation = 0.976 (95% CI: 0.963, 0.984).  The prediction equation from regression analysis was ([Fe])=0.80(R2*)-44.1(r=0.968, r2 = 0.937, p < 0.0001). Determination of liver iron concentration by R2* methods may be helpful as a diagnostic surrogate for Ferriscan® iron measurements.

14:30         4636.     Chronic Hepatitis and Fibrosis Assessed by Magnetic Resonance Elastography (MRE)

Yi Wang¹, Frank H. Miller¹, Robert McCarthy, Zongming E. Chen, Laura Sternick, Daniel Ganger, Richard Ehman², Reed Omary¹, Josh Levitsky, Bradley D. Bolster, Jr. ³, Saurabh Shah³, Sven Zuehlsdorff³, Paul Nikolaidis¹, Vahid Yaghmai¹

¹Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; ²Mayo Clinic; ³Siemens Healthcare

We proposed to evaluate the capability of MRE in detecting and distinguishing patients with inflammation and without fibrosis from patients without inflammation and fibrosis, and with various stages of fibrosis based on histopathologic analyses. Liver tissue with inflammation and without fibrosis can be seen with mildly elevated stiffness value on MRE, which was significantly higher than those that lack inflammation and fibrosis. Both mild hepatic fibrosis and inflammation was associated with mild elevation of stiffness, but a significant difference was not observed. Furthermore, tissue with moderate fibrosis and advanced fibrosis to cirrhosis showed significant increased stiffness values on MRE.

15:00         4637.     Diffusion Tensor Imaging of Liver Fibrosis in an Experimental Model

Jerry S. Cheung^1,2, Shu Juan Fan^1,2, Darwin Shan Gao^1,2, Kwan Man³, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ³Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong SAR, China

Early diagnosis of liver fibrosis could facilitate early interventions and thus alleviate its progression to cirrhosis and/or hepatocellular carcinoma. Several studies have shown that measurement of water diffusivity by diffusion-weighted imaging (DWI) was useful in the evaluation of liver fibrosis and cirrhosis. The aim of this study was to characterize longitudinal changes in diffusion properties of liver using diffusion tensor imaging (DTI) in an experimental model of liver fibrosis. The experimental results in this study demonstrated that DTI could detect longitudinal changes in diffusion properties of liver in an experimental model of liver fibrosis.

13:30         4638.     Diagnosis of Cirrhosis with MRI: Is Magnetization Transfer Contrast Worth Pursuing?

Andrew B. Rosenkrantz¹, Pippa Storey¹, Ben Niver¹, Cristina Hajdu², Vivian S. Lee¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States; ²Pathology, NYU Langone Medical Center, New York, NY, United States

8 patients with liver cirrhosis and 8 volunteers underwent liver MRI at 1.5T that included repeated applications of an adjustable magnetization-transfer contrast (MTC) sequence, with the MT pre-pulse offset frequency varying from 1000Hz to 3000Hz and the MT pre-pulse flip angle varying from 100º to 900º.  The magnetization transfer ratio measured over the right lobe showed substantial overlap between healthy and cirrhotic liver for all assessed MTC sequences, with none of the differences being significant (p-values from 0.092 to 0.819).  Our data suggests that, unlike the results of previous studies, MTC imaging is unable to differentiate healthy and cirrhotic liver.

14:00         4639.     Breath-Hold Quantitative Liver MR Imaging: Assessment of Hepatic Fibrosis, Iron Content, and Fat Fraction

Russell Norman Low^1,2, Huanzhou Yu³, Ann Shimakawa³, Lloyd Estkowski, Richard Ehman⁴

¹Sharp and Children's MRI Center, San Diego, CA, United States; ²San Diego Imaging, San Diego, CA, United States; ³Applied Science Lab, General Electric Healthcare; ⁴Mayo Clinic

Quantification of diffuse liver disease adds a new dimension to hepatic MR imaging which can provide critical information for diagnosis and for monitoring response to therapy. We explore the implementation of a rapid breath-hold MR evaluation of liver fibrosis using MR Elastography combined with a new multiecho Dixon technique known as IDEAL Quant which quantifies liver iron assessed by R2* values and fat fraction. In five breath holds this exam assesses liver fibrosis, R2* correlated with iron content, and the percentage of fatty infiltration.

14:30         4640.     Background Gradient Correction for Water and Fat Quantification in 2D Liver Imaging

Yoon Ho Nam¹, Hahnsung Kim¹, Dong-Hyun Kim^1,2

¹Electrical & Electronic Engineering, Yonsei University, Seoul, Korea, Republic of; ²Radiology, Yonsei University College of Medicine, Seoul, Korea, Republic of

Accurate quantification of the liver fat content is an important factor in detecting hepatic diseases. A multi-echo approach can be used effectively for liver fat quantification. However, the presence of macroscopic field inhomogeneities shortens T2* values and can lead to underestimated T2* values of fat content in liver. This study propose correcting method for these macroscopic inhomogeneities to accurately quantify T2* values and fat, water content using multi-echo 2D liver imaging.

15:00         4641.     Quantification of Hepatic Iron Overload: Usefulness of Echo-Planar Imaging Based Diffusion-Weighted Magnetic Resonance Imaging

Tatsuyuki Tonan¹, Kiminori Fujimoto¹, Aliya Qayyum², Takumi Kawaguchi³, Atsushi Kawaguchi⁴, Koji Okuda⁵, Shuji Nagata¹, Michio Sata³, Naofumi Hayabuchi¹

¹Radiology, Kurume University School of Medicine, Kurume, Fukuoka, Japan; ²Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; ³Internal Medicine, Kurume University School of Medicine, Kurume, Fukuoka, Japan; ⁴Biostatistics Center, Kurume University School of Medicine, Kurume, Fukuoka, Japan; ⁵Surgery, Kurume University School of Medicine, Kurume, Fukuoka, Japan

MRI is sensitive to tissue iron overload because iron leads to a decline of magnetic resonance signal due to T2-shortening effect related to the paramagnetic properties, and recently has become suitable technique for quantifying hepatic iron overload noninvasively. The aim of this study is to assess the usefulness of echo-planar image based diffusion- weighted image (EPI-DWI) for quantifying subtle hepatic iron stores. We found a good correlation between EPI-DWI and hepatic iron concentration in patients with viral hepatitis, and demonstrated that EPI-DWI was more sensitive sequence for quantifying hepatic iron overload than gradient-recalled echo sequence.

13:30         4642.     Multislice Multiecho T2* MRI for Detection of the Distribution of Hepatic Iron Overload.

Antonella Meloni¹, Antongiulio Luciani², Alessia Pepe¹, Vincenzo Positano¹, Gennaro Restaino³, Maria Chiara Dell'Amico¹, Brunella Favilli¹, Gianna Alberini¹, Giovanni Palazzi⁴, Massimo Lombardi¹

¹MRI Lab, “G. Monasterio Foundation” and Institute of Clinical Physiology, CNR, Pisa, Italy; ²Istituto di Radiologia Az. Osp. "Garibaldi", Catania, Italy; ³Catholic University, Campobasso, Italy; ⁴Policlinico di Modena, Modena, Italy

The goals of our study were to set up a MRI acquisition technique for the detection of the iron burden in the whole liver of thalassemia major patients. Significant differences in the segmental T2* values were found. Specifically, the mean T2* values over the segments VI and VIII were significantly lower than the mean T2* values over the other segments.  However, T2* variations in liver are low and likely due to the artefacts effects and measurement variability.

14:00         4643.     Hepatic Lipid Quantification with MRS: BMI, T2, and Prandial Correlations.

Robert D. O'Connor¹, Gary Skolnick², Nicole Nejedly², Adil Bashir¹, Samuel Klein²

¹Radiology, Washington University, St. Louis, MO, United States; ²Geriatrics and Nutritional Science, Washington University School of Medicine, St. Louis, MO, United States

MRS protocols for hepatic lipid quantification are examined.  It is concluded that an optimal protocol can achieve a CV of at least 5%.

14:30         4644.     Three-Dimensional Two-Point Dixon Acquisition with Projections Onto Convex Sets (POCS) for Abdominal Imaging

Agus Priatna¹, Vamsi Narra²

¹MR R&D Collaborations, Siemens Healthcare, St Louis, MO, United States; ²Mallinckrodt Institute of Radiology, Washington University, St Louis, MO, United States

Three-dimensional two-point Dixon technique has been routinely used for liver imaging to provide opposed and inphase images, as well as fat only and water only images. Phase partial Fourier and strong echo asymmetry are often employed to reduce the scan time. However, echo asymmetry and phase partial Fourier with zero filling result in blurring artifacts in the in-plane view.  This abstract describes the use of phase correction with projection onto convex sets (POCS) to the three dimensional two-point Dixon sequence in order to reduce blurring artifact and improve image quality at short scan times

15:00         4645.     Contribution of Phase-Contrast Magnetic Resonance Imaging in the Study of Hepatic Fibrosis: Preliminary Results

Thierry Yzet¹, Roger Bouzerar², Eric Nguyen-Khac³, Brice Robert¹, Denis Chatelain⁴, Hervé Deramond¹, Marc-Etienne Meyer², Olivier Baledent²

¹Radiology, University Hospital, Amiens, France; ²Imaging and Biophysics, University Hospital, Amiens, France; ³Hepato-Gastroenterology, University Hospital, Amiens, France; ⁴Pathological Cytology, University Hospital, Amiens, France

Hepatic fibrosis is secondary to many etiologies and quantification of this fibrosis is a key point for the clinician. In this work, we wanted to appraise the potential links between elastometry data and parameters measured using PC-MRI in 17 subjects developing hepatic pathologies. Three distinct groups, probably representative of  the stage of hepatic fibrosis, clearly appear A statistically significant linear correlation  between the elasticity modulus and the vessel area variations  DS or the portal congestion index IC is clearly highlighted. PC-MRI could be a useful and complementary tool for the understanding of evolution mechanisms involved in hepatic fibrosis.

Metabolism Liver & Other II

14:00         4646.     Absolute Quantification of Liver Fat by MRI Fat Volume Fractions in Comparison to Histopathology - not available

Michael Alexander Fischer¹, Paul Stolzmann¹, Daniel Nanz¹, Cäcilia S. Reiner¹, Stefan Breitenstein², Matteo Montani³, Borut Marincek¹, Hans Scheffel¹

¹Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland; ²Clinic of Visceral and Transplant Surgery, University Hospital Zurich, Zurich, Switzerland; ³Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland

A new approach for absolute quantification of liver fat content is presented by calculation of fat volume fractions (FVF-MRI) derived from a single-breathhold 3D spoiled dual gradient-echo MRI sequence yielding for in-/out-of-phase as well as fat-signal only images. Our results show that the absolute liver fat content equalling the actual weight per volume of liver lipid can be quantified accurately by FVF-MRI with surface-coil sensitivity correction compared to fat volume fractions derived from histopathology as the gold standard. Moreover fat-only images significantly reduce the measurement bias as compared to in/out-of-phase images.

14:30         4647.     Optimization of a 3D Dixon MR Imaging Techniques for Fat / Water Quantitation

sunder s. rajan¹, David Thomasson², Ronald Ouwerkerk³, songtao liu³, Ahmed m. Gharib³

¹Div of physics, fda/cdrh/osel, Silver Spring, MD, United States; ²Radiology & Imaging Sciences, National Institutes of Health, MD; ³National Institute of Digestive and Diabetes and Kidney Diseases

Using a well characterized serial dilution lipid-water phantom we were able to simulate signal intensity results to determine the appropriate range of sequence parameter values over which we could experimentally validate measured lipid-water ratios on existing clinical 2D technique as well as using a recently available 3D Dixon technique.

15:00         4648.     Measurements of the Abdominal Fat Area: Comparison with MR and CT Measurements in Medical Check-Ups

Takayuki Masui¹, Motoyuki Katayama¹, Rie Takafuji², T Natume¹, S Nozawa², Hiroki Ikuma¹, Kimihiko Sato¹, Kenji Asano³, Hasnine A. Haque³, M Sugimura¹, S Imamura², Atsushi Nozaki³

¹Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan; ²Seirei Kenshin Center, Hamamatsu, Japan; ³GEHC-Japan, Hino, Japan

As one of criteria for metabolic syndrome, measurements of abdominal fat area using CT have been suggested. MEDAL or LAVA flex can provide in-phase and fat images and, modification of these images can be utilized to set threshold to make semiautomatic calculation of fat area. Purpose was with semiautomatic demarcation of fat areas on MR to evaluate correlations between MR and CT measurements for abdominal fat area in subjects having medical check-ups. Good correlation was observed between in MR and CT measurements. CT measurements of abdominal fat can be replaced by MR without irradiation in large population for medical-checkups.

15:30         4649.     Hepatic Fat Quantification on 3T MRI Using a Dual-Flip Multi-Echo Sequence with MR Spectroscopy and Histopathologic Correlation

Hero K. Hussain¹, Marko K. Ivancevic, Frank J. Londy, Susan Rohrer, Elif A. Oral, Barbara McKenna, Thomas L. Chenevert

¹University of Michigan, Ann Arbor, MI, United States

The dual-flip multi-echo MRI method at 3T is reliable to measure hepatic fat. It correlates well with MRS and quantitative histopathologic measures, though unlike MRS, offers full-liver mapping of fat content and heterogeneity.

13:30         4650.     Multislice Multiecho T2* MRI Assessment of Regional Pancreatic Iron Overload and Correlation with Cardiac Biventricular Function and Myocardial Iron Overload in Thalassemia Major Patients.

Gennaro Restaino¹, Antonella Meloni², Alessia Pepe², Vincenzo Positano², Massimiliano Missere¹, Pasquale Pepe², Daniele De Marchi², Giuseppina Secchi³, Antongiulio Luciani⁴, Giuseppina Sallustio¹, Massimo Lombardi²

¹Catholic University, Campobasso, Italy; ²MRI Lab, “G. Monasterio Foundation” and Institute of Clinical Physiology, CNR, Pisa, Italy; ³Azienda USL n° 1, Sassari, Italy; ⁴Istituto di Radiologia Az. Osp. "Garibaldi", Catania, Italy

The aims of this study were to describe the T2* values of the pancreas in patients with TM, to investigate the correlation between pancreatic and myocardial siderosis and to investigate the correlation between pancreatic iron overload and biventricular cardiac function. The mean T2* over the pancreatic head was significantly higher than the mean T2* value over the pancreatic body and tail. Significant positive correlations of the pancreatic T2* were demonstrated for global heart T2* value and number of segments with normal T2*. Moreover, pancreatic iron overload was negatively correlated to biventricular systolic function.

14:00         4651.     The Use of Slope-Ratio Methods to Quantify Liver Perfusion from Dynamic Contrast-Enhanced MR Data: Comparison with Perfusion Quantification Using a Dual-Input Single Compartment Model

Keiko Miyazaki¹, Matthew R. Orton¹, James A. d'Arcy¹, Val Lewington², Dow-Mu Koh³, Martin O. Leach¹, David J. Collins¹

¹CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom; ²Department of Nuclear Medicine, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ³Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

Dynamic contrast-enhanced (DCE-) MRI is a technique that enables non-invasive interrogation of tissue microvasculature environment. Different analysis approaches can be taken to quantify arterial and portal-venous hepatic perfusion from liver DCE-MRI data. In this study, two slope-ratio methods were used to quantify arterial and portal-venous perfusion from clinical MR data. Comparisons were made with perfusion quantified using a dual-input single compartment model. Perfusion quantified using the slope-ratio methods were found to be lower than those quantified using the dual-input model. High correlations were observed between the two approaches, especially in the estimates of arterial perfusion.

14:30         4652.     Does the Measurement of Liver and Vertebral Fat Content Influenced by R2* Effect in T2*-IDEAL: A Comparison Study with 3-Point IDEAL and MRS in Healthy Volunteers

Chun-Jung Juan¹, Hing-Chiu Chang^2,3, Chih-Yung Yu¹, Chang-Hsien Liou¹, Cheng-Yu Chen¹, Chun-Jen Hsueh¹, Hung-Wen Kao¹, Chih-Wei Wang¹, Hsiao-Wen Chung^1,3, Guo-Shu Huang¹

¹Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; ²Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; ³Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan

By simultaneous acquisition of all echoes in one TR interval, T2* IDEAL is superior to 3-pt IDEAL by allowing either larger spatial coverage or higher resolution. Whether the fat content measured by the T2* IDEAL method is influenced by the R2* effect of tissue or not is an important concern but remains ambiguous. In this study, we verify the fat content measurements of liver (lower R2* value) and vertebra (higher R2* value) in both methods compared to the MRS method. Our results show no statistical difference of liver and vertebral fat content in T2* IDEAL and 3-pt IDEAL methods.

15:00         4653.     R2* Measurement Using Absolute SNR-Weighted Least Square Regression

Xiaoming Yin^1,2, Saurabh Shah³, Andrew C. Larson^1,2

¹Radiology, Northwestern University, Chicago, IL, United States; ²Electrical Engineering and Computer Science, Northwestern University, Evanston , IL, United States; ³Siemens Medical Solutions, Chicago, IL, United States

R2* is typically estimated via mono-exponential fitting of signal decay within a series of GRE images combined by the root sum-of-square (RSS) approach. However, RSS approaches rectify and bias noise in later TEs, resulting in systematic fitting errors for R2* estimation. Our work investigated the accuracy of low SNR R2* measurements for RSS reconstructed data.  Through phantom, ex vivo, and volunteer studies, we compared the accuracy of R2* measurement using SNR-weighted least-square regression and SNR-based truncation methods. We found SNR-weighted least-square regression to be a simple and reliable approach to reduce R2* measurement error.

13:30         4654.     Differentiation of T1W Hyperintense Nodules Among Cirrhotic Liver: Comparison of Ferucarbotran-Enhanced MR Imaging with Accumulation Phase FS-T1WI and Gadolinium-Enhanced MR Imaging - not available

Ran-Chou Chen^1,2, Chen-Te Chou^3,4

¹Biomedical Imaging and Radiological Science, National Yang-Ming Medical University, Taipei, Taiwan; ²Radiology, Taipei City Hospital , Taiwan; ³Radiology, Chang-Hua Christian Hospital, Er-lin branch, Chang-Hua, Taiwan; ⁴Department of Biomedical Imaging and Radiological Science, National Yang-Ming Medical University, Taipei, Taiwan

Our study was to evaluate ferucarbotran-enhanced MRI with accumulation-phase fat suppression T1-weighted imaging in comparison with gadolinium-enhanced MRI for characterization of T1W hyperintense nodules within cirrhotic liver. In the gadolinium-enhanced group, the MRI sensitivity, specificity and accuracy were 60%, 100% and 73%, respectively. In ferucarbotran-enhanced group, the sensitivity, specificity and accuracy were 100%, 83% and 94%, respectively. The ferucarbotran-enhanced MRI provided additional information of cellular function in differentiation of focal hepatic lesion and ferucarbotran-enhanced MRI is superior to gadolinium-enhanced MRI in characterization of T1W hyperintense nodules. T1W hyperintense nodule depicting hyperintense on ferucarbotran-enhanced accumulation-phase FS-T1WI should be investigated aggressively.

14:00         4655.     Utilizing Magnetic Resonance Elastography in the Evaluation of Liver Donors

Tilina Hu¹, Alvin Silva¹, Leland Hu¹, Richard Ehman²

¹Radiology, Mayo Clinic, Scottsdale, AZ, United States; ²Radiology, Mayo Clinic, Rochester, MN, United States

To determine accurate biopsy-validated Magnetic Resonance Elastography threshold values that distinguish normal from abnormal liver (due to fibrosis and/or inflammation).  We focus specifically on pre-operative evaluation of liver donors prior to transplant.

14:30         4656.     DTI and 2D MR Spectroscopy of Hepatitis C in 3T

Rajakumar Nagarajan¹, Manoj K. Sarma¹, Charles Hinkin², Steven Castellon², Jason P. Smith³, Homayoon Khanlou⁴, Laveeza Bhatti⁴, Jonathan Truong⁵, Ann B. Ragin⁶, Elyse Singer⁷, M Albert Thomas¹

¹Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States; ²Department of Psychiatry & Biobehavioral Sciences, UCLA School of Medicine and VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States; ³Veteran's Affairs Greater Los Angeles Healthcare Center; ⁴AIDS Healthcare Foundation, Westside Clinic, Los Angeles; ⁵Kaiser Permanente, Lancaster CA; ⁶Northwestern University, Chicago, Illinois, USA; ⁷Neurology, UCLA School of Medicine, Los Angeles, California, United States

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). HCV infection sometimes results in an acute illness, but most often becomes a chronic condition that can lead to cirrhosis of the liver and liver cancer. Hepatitis C may be detectable with MR diffusion tensor imaging (DTI), which is exquisitely sensitive to water diffusion and is used to quantify the magnitude of diffusivity and the orientation and linearity (that is, anisotropy) of water motility in microstructural level in brain. Combining two-dimensional (2D) localized correlated spectroscopic (L-COSY) technique with DTI provides more information about the cerebral metabolites, mean diffusivity and fractional anisotropy changes in patients with hepatitis C.

15:00         4657.     Estimation of Liver Iron Content with Different MRI Methods

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

¹Dept. for Diagnostic and Interventional Radiology, Univ.-Clinic Ulm, Ulm, Baden-Württemberg, Germany; ²Pediatrics, Univ.-Clinic Ulm, Ulm, Germany; ³Hematology, Univ.-Clinic Ulm, Ulm, Germany

To compare the liver iron content (LIC) determined by different MR methods, we investigated 93 patients with protocols according to three published methods, two using gradient echo (GRE) sequences and one working with spin echo (SE). The methods correlate moderately with r=0.82. Weakpoints are the bad performance of one GRE method near its upper limit and the sensitivity to liver steatosis of the GRE method addressing high LIC. The latter leads to reduced correlation of SE vs. GRE in the high LIC range. Although GRE generally tends to overestimate LIC, both methods are suitable for decisions concerning patient management.

13:30         4658.     Is Shear Viscosity a Sign for Malignancy in Liver Tumours?

Jean Luc Daire¹, Ralph Sinkus², Mathilde Wagner¹, Nathalie Haddad¹, Valerie Vilgrain¹, Bernard van Beers¹

¹INSERM U773, CRB3 Centre de Recherches Biomédicales Bichat-Beaujon, Paris, France; ²Institut Langevin, ESPCI, Paris, France

Liver tumours are very frequent. They include benign lesions and malignant primary or secondary tumours (metastases). Currently, there is no established non-invasive imaging Goldstandard available in order to characterize malignancy for liver tumours. Very often, the enhancement characteristics of a bolus are used in order to differentiate benign from malignant tumours. Here, we intend to prospectively evaluate the complex shear modulus   as measured via MR-elastography in the assessment of malignancy or benignity of liver lesions and compare its performance to those of three enhancement characteristics of the bolus passage.

14:00         4659.     Evaluation of Nonalcoholic Liver Disease Using ²³Na MRI and Shift Reagent-Aided ²³Na and ³¹P MRS

Paige Nicole Hopewell^1,2, Navin Bansal^1,2

¹Radiology, Indiana University School of Medicine, Indianapolis, IN, United States; ²Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States

Changes in signal intensity with disease progression in single quantum (SQ) and triple quantum-filtered (TQF) ²³Na MRI are validated with shift reagent-aided SQ and TQF ²³Na and ³¹P MRS studies in a nonalcoholic fatty liver disease model. Changes in intracellular Na⁺ concentration and fibrosis-associated macromolecule deposition in the extracellular space both contribute to an increased TQF ²³Na MRI signal with advanced disease progression.

14:30         4660.     Liver Fibrosis Grading Based on MR Elastography and 31P Spectroscopy

Edmund Mark Godfrey¹, Anant S. Krishnan¹, Susan E. Davies², Nyree M. Griffin³, Graeme J. Alexander⁴, Mike E. Allison⁴, Alexander E. Gimson⁴, William H. Griffiths⁴, David J. Lomas¹

¹Department of Radiology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; ²Department of Histopathology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; ³Department of Radiology, St Thomas' Hospital, London; ⁴Department of Hepatology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

Standard imaging techniques are insensitive to liver fibrosis. Current clinical assessment of liver fibrosis requires a biopsy, which risks complications and sampling error. This work describes our experience with 2 new MR techniques: MR elastography and 31P spectroscopy. MR elastography was found to correlate with histological grade of fibrosis in contrast to 31P PME/PDE ratio. Our findings do not correlate with previous work. This may be because histological grade in our study was based on the original report, rather than review of the biopsy material. We plan to repeat the analysis of our results with this data.

15:00         4661.     Use of a Two-Point Dixon VIBE Sequence for Post-Contrast Liver MRI: Comparison with Standard Chemically-Selective Fat-Suppressed VIBE for Image Quality and Lesion Detection

Andrew B. Rosenkrantz¹, Lorenzo Mannelli¹, Sungheon Kim¹, James Babb¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States

In 30 consecutive patients at 1.5T, a breath-hold two-point Dixon VIBE acquisition was obtained of the liver immediately following a standard chemically-selective fat-suppressed VIBE acquisition, both performed during the equilibrium phase after intravenous contrast administration.  Compared with the standard VIBE sequence, the Dixon VIBE sequence demonstrated significantly improved strength of fat suppression, homogeneity of fat suppression, vessel sharpness, and subjective overall image quality.  There were no significant differences between the two sequences for sensitivity or PPV for focal liver lesion detection.  We conclude that Dixon-VIBE achieved higher image quality with preserved diagnostic ability for post-contrast liver MRI.

Bowel

14:00         4662.     Fast 3D Tracking of 19F Labeled Small Capsules for Combined Morphology and Real-Time Flow Studies in the Gastrointestinal Tract

Tobias Hahn¹, Sebastian Kozerke¹, Mark Fox^2,3, Werner Schwizer², Andreas Steingoetter, ^1,4, Michael Fried², Peter Boesiger¹

¹Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland; ²Division of Gastroenterology and Hepatology, University Hospital Zurich; ³Nottingham Digestive Diseases Centre and Biomedical Research Unit Queen's Medical Centre, University Hospital Nottingham; ⁴Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.

3D tracking of small-sized 19F labeled capsules is studied using fast modified balanced FFE sequences for concurrent measurements of gastrointestinal function and morphology. Perfluoro-15-crown-5-ether and Hexafluorobenzene are proposed and studied for use as tracking mediums. The proposed imaging protocol is shown to be reliable in tracking small capsules through realistic abdominal phantoms and might therefore bear potential of being a valuable tool in detecting abnormal gastric function and at the same time posing the basis for creating a 3D anatomical model of the complex bowel geometry.

14:30         4663.     MR Fluoroscopy for Gastrointestinal Malrotation in Unsedated Infants

Owen John Arthurs¹, Ilse Joubert¹, Martin John Graves¹, Pat Set¹, David John Lomas¹

¹Department of Radiology, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

Gut malrotation is a congenital disorder of abnormal intestinal rotation, for which the current diagnostic technique is an upper GI X-ray contrast study. This study evaluated the feasibility of interactive MR fluoroscopy for defining the gastro-intestinal tract anatomy in un-sedated children with suspected malrotation. We imaged 9 children using both X-ray fluoroscopy, FIESTA and interactive SSFSE MR imaging. We confidently identified the DJ flexure (7/9; 77%), orientation of the SMA / SMV (8/9; 88%) and the caecum (9/9; 100% using MRI. Interactive MR Fluoroscopy is feasible for gut imaging in un-sedated children.

15:00         4664.     Customised Rotational Imaging Support for Paediatric MRI (CRISP-MRI)

Owen John Arthurs¹, Erich Zammer², David John Lomas¹

¹Department of Radiology, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; ²Department of Orthopaedics, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

Traditional X-ray fluoroscopy methods for upper gastro-intestinal (GI) tract imaging in children require postural alteration to help move contrast media to the required locations. In order to establish an equivalent MRI technique for imaging the paediatric gut, we have developed a custom-built coil insert which allows for gentle rotation of a child within a rigid surface coil. It has a Vitrothene polymer backing, with a Plastazote foam insert, which is currently for orthopaedic supports in our hospital. These materials are strong, non-ferromagnetic, easily cleanable, lightweight and breathable. This type of device should help facilitate MR fluoroscopy in small children.

15:30         4665.     Colonic Response to an Experimental Model of Human Diarrhoeal Disease

Elisa Placidi¹, C. L. Hoad¹, L. Marciani², R. C. Spiller², P. A. Gowland¹

¹SPMMRC, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom; ²Nottingham Digestive Diseases Centre Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom

MRI was used to investigate the colonic response to two contrasting test meals: a readily absorbable glucose drink (control) and a non absorbable mannitol drink, which acts as a model of acute diarrhoeal disease. Eight healthy volunteers were imaged on a 1.5 T Philips Achieva scanner with several sequences up to 8 hours after the drink, to assess changes in the ascending colon in terms of water content, volume, and image signal intensity. Differences between the two conditions have been quantified. A scoring system based on subjective assessment of colonic contents has also been developed.

13:30         4666.     Comparison Study on Differentiating Active from Remissive Crohn’s Disease by 3.0T and 1.0T MRI

Ambreen Sattar¹, J Zhu², Y Yu², L Hamm², Y Ye², Y Xuan², J Hu²

¹Radiology, Wayne State University, Detroit, MI, United States; ²WSU MR RESEARCH, Wayne State University, detroit, MI, United States

This study analyzes the abiltiy of 3.0 T MRI to better evaluate the activity of active vs remissive Crohn's disease over 1.0 T MRI.3.0 T magnet is better capable of detecting various signs of active Crohn's diseases such as Stenosis, bowel wall thickening and bowel wall enhancement. MRI is safer option because it does not uses ionizing radiation and provides better diagnostic outcome in staging disease which can significantly alter treatment options offered by the physician.

14:00         4667.     Performance of  Non-Contrast MR Enterography to Localize and Predict Disease Activity in Crohn's Disease.

Srigouri Yalamanchili¹, Michael Macari¹, Rafael Rivera¹, Danny Kim¹, Alec Megibow¹, James Babb¹, Joseph Levy¹, Kerry Zabriskie¹, Sooah Kim²

¹New York University; ²New York University, New York, NY, United States

Secific findings at MR imaging- mural T2 high signal intensity and contrast enhancement patterns- have been proposed as accurate markers of disease activity. The purpose of our study is to assess the performance using conventional non-contrast MR imaging sequences as a tool to localize and predict disease activity in Crohn’s disease in comparison to post-contrast images. Thirty patients referred for MR enterography were evaluated at 1.5 T using steady state free precession, single shot fast spin echo, fat suppressed T2, and pre- and post contrast enhanced T1-weighted sequences. Images were reviewed by two radiologists in two separate sessions; the readers interpreted non-contrast images of MRI during the first session and whole images including post-contrast sequences during the second session. The readers evaluated the presence or absence of disease in regard to the presence of active inflammation using a six-point grading system (0, No evidence of disease; 1, definite absence of active inflammation; 2, probable absence of active inflammation; 3, equivocal; 4, probable presence of active inflammation; and 5, definite presence of active inflammation). Reference standard was constructed by combining surgical, endoscopy, physical, and all available imaging findings. There were 34 bowel segments with active inflammation on reference standard in 18 subjects (proximal ileum, n=1, distal ileum, n=4; terminal ileum, n=16; cecum, n=6; ascending colon, n=1; rectosigmoid, n=2). Inter-reader agreement was significantly higher for whole imaging including post-contrast images relative to non-contrast images (Kappa 0.31 for non-contrast and 0.41 for whole images). Although there is no significant difference localizing abnormal bowel segment involved with Crohn’s disease using non-contrast images, inter-reader agreement, sensitivity, and accuracy are significantly higher in the assessment of active disease adding post-contrast images to non-contrast images for MRI interpretation.

14:30         4668.     The Effect of High Fat or High Carbohydrate Meals on the Gastrointestinal Tract: A MRI Study

Eleanor F. Cox¹, Michael Mellows², Susan E. Pritchard¹, Mahamoud Hussein¹, Caroline L. Hoad¹, Carolyn Costigan³, Luca Marciani², Robin C. Spiller², Penny A. Gowland¹

¹SPMMRC, Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; ²Nottingham Digestive Diseases Centre, NIHR BRU, Nottingham University Hospitals, Nottingham, United Kingdom; ³Brain & Body Centre, University of Nottingham, Nottingham, United Kingdom

The effect of a high fat (HF) meal and an equicaloric high carbohydrate (HC) meal on satiety, gastric volumes, small bowel water content (SBWC) and gallbladder contraction (as a marker of CCK release) was investigated using MRI. The HF meal resulted in increased fullness and decreased hunger and appetite compared with the HC meal. Gastric emptying was initially faster for the HF meal. After 90 minutes, SBWC was greater after the HF meal than after the HC meal. This delayed increase may reflect delayed emptying of fat which stimulates pancreatic secretions.

15:00         4669.     The Use of MR Thermometry in Legal Medicine: A Feasibility Study Utilizing Rat Rectal Temperature.

Hideto Kuribayashi¹, Fanlai Cui², Keiko Hirakawa², Yoshimasa Kanawaku³, Youkichi Ohno²

¹Varian Technologies Japan Limited, Minato-ku, Tokyo, Japan; ²Nippon Medical School; ³National Defence Medical College

Proton resonance frequency-shift based MR temperature imaging was introduced into the rectal temperature measurement in cooling dead bodies in order to estimate the time of death in legal medicine.  A series of MR temperature difference maps in cooling dead rats could be obtained.  Moreover, distribution of cooling rates among pelvic tissues was observed and shown to be related to body position.

Female Pelvis MRI

13:30         4670.     Clinical Significance of the 2 Ppm Resonance in In-Vivo 1H-MR Spectroscopy of Ovarian Tumors

Mayumi Takeuchi¹, Kenji Matsuzaki¹, Masafumi Harada¹, Hiromu Nishitani¹

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

We evaluated 31 ovarian tumors including 8 mucinous tumors by 1H-MR spectroscopy at 3T. High to moderate 2 ppm peaks were observed in all 8 mucinous tumors, whereas low to slight 2 ppm peaks were observed in 14 of 23 non-mucinous tumors. The 2 ppm concentration in mucinous tumors (7.39+/-2.85 mM) was significantly higher than that in non-mucinous lesions (3.12+/-1.42 mM) (p<0.005). Using a cut off value of 4.45 mM for mucinous tumors had a sensitivity of 88%, specificity of 86%, PPV of 78%, and NPV of 92%.

14:00         4671.     Differentiation of Benign and Malignant Uterine Corpus Tumors: Value of 1H-MR Spectroscopy at 3T

Mayumi Takeuchi¹, Kenji Matsuzaki¹, Masafumi Harada¹, Hiromu Nishitani¹

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

We evaluated 32 uterine corpus tumors (14 malignant including 11 endometrial carcinomas and 3 myometrial tumors; 18 benign including 5 endometrial and 13 myometrial masses) by 1H-MR spectroscopy at 3T. Choline peaks were observed in all 32 lesions, and tended to show higher peaks in malignant tumors. The choline concentration in malignancy (8.77+/-1.91 mM) was significantly higher than that in benign lesions (4.82+/-2.23 mM) (p<0.0001). Using a cut off value of 7.00 mM for malignant lesions had a sensitivity of 93%, specificity of 83%, PPV of 94%, and NPV of 81%.

14:30         4672.     23Na/1H MR Imaging of Female Pelvis at 7T Using a Dual-Tuned Multi-Channel Body Coil - not available

Kyongtae Ty Bae¹, Jung-Hwan Kim¹, Chan Hong Moon¹, Alessandro Furlan¹, Bumwoo Park¹, JinHong Wang¹

¹University of Pittsburgh, Pittsburgh, PA, United States

For the first time, we were able to demonstrate MR imaging of the female pelvis and distribution of sodium signal intensities in the female pelvic organs in normal subjects at 7T with a multi-channel dual-tuned body RF coil. Future development of 23Na MR imaging will concentrate on the  clinical application of sodium MR imaging of the female pelvis to assess various physiological and pathological conditions accompanied with changes in sodium concentration.

15:00         4673.     In Vivo ³¹P MR Spectroscopy of Human Placenta

Jan Weis¹, Kathrine Bjersand², Anna Karin Wikström², Mats Olovsson², Johan Wikström³

¹Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Uppsala, Sweden; ²Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden; ³Department of Oncology, Radiology and Clinical Immunology, Uppsala University , Uppsala, Sweden

31P image-selected in vivo spectroscopy (ISIS) with proton decoupling and nuclear Overhauser effect enhancement was used for measurement the spectra of placental tissue in vivo. Major metabolites of normal human placenta and placentas from women with preeclampsia were quantified. Our results demonstrate that the 31P MRS is able to measure spectra of the placenta with acceptable quality and measurement time. 31P MRS is a promising tool to detect in vivo changes of human placental metabolites.

13:30         4674.     Pre- And Postoperative Dynamic MRI: Evaluation of Pelvic Organ Prolapse in Symptomatic Women - not available

Céline D. Alt¹, Kerstin Brocker², Florian Lenz², Christof Sohn², Hans-Ulrich Kauczor¹, Peter Hallscheidt¹

¹Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany; ²Obstetrics and Gynecology, University Hospital Heidelberg, Heidelberg, Germany

Description: Evaluation of dynamic changes of pelvic organ prolapse by MRI. Method: Dynamic 1.5T MRI was performed preoperative and after surgery in women with pelvic organ prolapse. For measurement two referential lines and four anatomical landmarks were taken. Results: 77 women were yet included. Surgical treatment was anterior (43/62), posterior (15/62) and combined anterior/posterior mesh-repair (4/62). Median values of organ prolapse often showed significant changes (p<0,05) in short term follow-up compared to preoperative results. With posterior mesh-repair the changes weren´t significant. Conclusion: Dynamic MRI offers an accurate extent of prolapse and allows to evaluate the success after reconstructive surgery.

14:00         4675.     Development of MR Visible Mesh for Soft Tissue Reinforcement in Surgical Treatment of Genital Prolapse. - not available

Sébastien Blanquer^1,2, Olivier Guillaume^1,2, Laurent Lemaire^3,4, Florence Franconi⁵, Xavier Garric^1,2, Jean Coudane^1,2

¹CNRS UMR 5247, Montpellier, France; ²UFR Pharmacie - Université Montpellier I, Montpellier, France; ³Université Angers, Angers, France; ⁴INSERM U646, Angers, France; ⁵PIAM, Université Angers, Angers, France

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14:30         4676.     Differentiation of Benign and Malignant Solid Components of Ovarian Masses by Diffusion-Weighted MR Imaging with ADC Measurement

Mayumi Takeuchi¹, Kenji Matsuzaki¹, Hiromu Nishitani¹

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

We evaluated surgically proven 52 ovarian tumors (36 malignant; 6 borderline malignant; 10 benign). All 42 malignant/borderline malignant tumors showed homogeneous or heterogeneous high intensity on DWI, whereas 3 of 10 benign tumors (3 thecomas) showed high intensity. The ADCs in 42 malignant/borderline malignant tumors and in 10 benign tumors were 1.02 +/- 0.19 and 1.38 +/- 0.30, respectively (p<0.001). Using a cut off ADC of 1.15 had a sensitivity of 76%, specificity of 80%. The ADCs in high intense 3 thecomas on DWI were relatively low (1.08 to 1.20), possibly due to their abundant cellular nature as functioning tumors.

15:00         4677.     Functional MRI of the Uterus with Quantitative T2, Diffusion-Weighted, and Magnetization-Transfer Contrast Imaging

Srigouri Yalamanchili¹, Genevieve L. Bennett¹, Pippa Storey¹, Andrew B. Rosenkrantz¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States

5 female volunteers underwent pelvic MRI at 1.5T that included T2-mapping, diffusion-weighted imaging, and magnetization-transfer contrast imaging, each performed through the uterus in the sagittal plane with matching slice positions.  There were trends toward a longer T2 time within the endometrium, a lower ADC within the junctional zone, and a lower magnetization-transfer ratio within the myometrium. There was a moderate positive correlation between T2 and ADC, but poor correlation between T2 and MTR as well as between ADC and MTR, suggesting that MTR may reflect a characteristic of tissue not measured by either ADC or T2.

Renal MR Imaging

14:00         4678.     Renal Perfusion and Oxygen Bioavailability in Swine: Comparing Isoflurane to Propofol

Logan Dance¹, Andrew Wentland², Nathan Artz², Sean Fain^1,2, Arjang Djamali³, Elizabeth Sadowski¹

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

Blood oxygen level dependent (BOLD) and arterial spin labeling (ASL) MR imaging can analyze the drug-specific effects of anesthetics on regional perfusion. Conflicting data currently exists regarding isoflurane's effect on renal perfusion. Using a swine model, we found that isoflurane decreased renal perfusion (ASL; microspheres) and renal oxygen bioavailability (BOLD MR) when compared to propofol. Isoflurane also caused a significant increase in heart rate and decrease in mean arterial pressure, compared to propofol. These effects should be considered when designing kidney perfusion studies.

14:30         4679.     Blood Oxygen-Level Dependent (BOLD) MR Imaging of Diabetic Nephropathy-Preliminary Study - not available

Zhen Jane Wang¹, Rahi Kumar¹, Benjamin M. Yeh¹, Suchandrima Banerjee², Chi-yuan Hsu³

¹Department of Radiology and Biomedical Engineering, University of California, San Francisco, San Francisco, CA, United States; ²Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; ³Department of Medicine, Division of Nephrology, University of California, San Francisco, San Francisco, CA, United States

The preliminary data showed decreased medullary R2* values (corresponding to increased oxygen bioavailability) in patients with diabetic kidney disease compared to healthy volunteers; and the decrease in medullary R2* values appeared to be related to the degree of kidney disease.

15:00         4680.     Free Breathing Renal BOLD Signal Frequency Assessment Following Diuresis

Brendan Boyd¹, Michael D. Noseworthy²

¹School of Biomedical Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; ²Electrical and Computer Engineering, School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada

Real time, free breathing, T2*-weighted (BOLD) images of the kidneys were retrospectively motion corrected and analyzed for physiologic spectral energies.  Following induced diuresis a corresponding decrease in cardiac BOLD signal frequency energy was observed in the renal cortex.  We hypothesize this corresponds to a decrease in O₂ utilization due to decreased renal H₂O reabsorption.

15:30         4681.     Functional Renal Imaging with BOLD: Validation of a Model for R2* in Kidney Cortex and Medulla

Jeff Lei Zhang¹, Henry Rusinek¹, Hersh Chandarana¹, Pippa Storey¹, Eric E. Sigmund¹, Pierre Hugues Vivier^1,2, Qun Chen¹, Hua Guo¹, Vivian S. Lee¹

¹Department of Radiology, New York University, New York, NY, United States; ²Rouen University Hospital, Rouen, France

In this study we used a Monte Carlo simulation approach to explore the mechanism of BOLD R2* contrast in kidney. Kidney pO2 levels predicted based on R2* values by the simulation were in agreement with literature values for a healthy volunteer, and correlated well with pO2 values measured by microprobe for diabetic rats of a previous study. The results indicate that the approach is a promising tool for quantifying kidney oxygenation level based on BOLD data.

13:30         4682.     Effect of Octreotide on Intra-Renal Oxygenation as Estimated by BOLD MRI in Rats - not available

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

¹Radiology, Northshore University Healthsystem, Evanston, IL, United States

Previous observations have shown lower intra-renal oxygenation as early as two days after induction of type I diabetes. In order to test the hypothesis that this may be related to the direct effect of hyperglycemia, the infusion of glucose solution was used in healthy rats. However comparable levels of blood glucose levels and R2* values in diabetic rats were observed only in animals pretreated with an insulin inhibitor (octeotride).  Because octeotride is associated with vasoconstriction, it is necessary to know the magnitude of any direct effect of octeotride on renal oxygenation.  That was the motivation for the present study.

14:00         4683.     BOLD Changes After Revascularization in Renal Artery Stenosis Patients - Preliminary Results

Iosif Alexandru Mendichovszky¹, Constantina Chrysochou², David L. Buckley³, Alan Jackson¹, Phil A. Kalra²

¹Wolfson Molecular Imaging Centre, The University of Manchester, Manchester, United Kingdom; ²Renal Department, Salford Royal Hospital, Salford, United Kingdom; ³University of Leeds, Leeds, United Kingdom

Atheromatous renovascular disease is a commonly encountered yet challenging disease to manage. The aim of the current study was to investigate renal parenchymal BOLD response to renal artery revascularization in patients with severe renal artery stenosis and correlate imaging findings with changes in SK-GFR (as measured by radioisotope techniques). No significant differences were found regarding baseline SK-GFR between kidneys that improved, remained stable, deteriorated or controls. R2* values were significantly higher in kidneys whose renal function subsequently improved vs. those who stayed stable, deteriorated or controls. In addition, the ratio of R2* to SK-GFR was significantly greater in improver kidneys.

14:30         4684.     Long Term Follow-Up of Human Transplanted Kidneys by DWI and BOLD Imaging - not available

Peter Vermathen¹, Tobias Binser¹, Chris Boesch¹, Ute Eisenberger², Harriet C. Thoeny³

¹Dept. Clinical Research, University Bern, Bern, Switzerland; ²Dept. of of Nephrology and Hypertension, University Hospital of Bern, Bern, Switzerland; ³Dept. of Radiology, University Hospital of Bern, Bern, Switzerland

Previously, we performed a DWI and BOLD MRI study in renal allograft recipients with good allograft function and determined short term reproducibility of diffusion and oxygenation parameters. In the current study, nine patients of our initial study were measured again 32±2 months after the initial scan to assess long term effects on diffusion parameters and on R2*. The functional parameters were markedly stable after 32 months with a slight tendency towards reduced oxygenation in eight of the nine patients, who still had good allograft function. In contrast, one subject with decreased GFR indicative of renal dysfunction demonstrated strongly altered MR-parameters.

15:00         4685.     Performance of Generalized Factor Analysis of Dynamic Sequence (GFADS) in the Automated Characterization of Renal Function and Tissue Enhancement in Dynamic Magnetic Resonance Imaging (MRI)

Ruth Lim¹, Jinsong Ouyang¹, Matthew D. Schmitz¹, Michael S. Gee¹, Ranu Shailam¹, Raul N. Uppot¹, Georges El Fakhri¹

¹Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, United States

We assessed the performance of a novel generalized factor analysis of dynamic sequences (GFADS) in dynamic, contrast-enhanced renal magnetic resonance imaging (MRI). By detecting unique time-intensity curves for each renal tissue/compartment type, this technique automates the creation of regions of interest (ROIs) around and within the kidneys, and obviates the need for manually-drawn ROIs. These time factor curves are computed from entire factor images and are significantly less affected by noise than time-intensity curves computed within regions of interest that span a few voxels. In this study, we found that GFADS software can successfully, semi-automatically, and rapidly identify the renal cortex, medulla, and collecting system on dynamic contrast-enhanced renal MRI studies while obviating the need to use manually-drawn regions of interest.  This enables detailed quantitative assessment of cortical and medullary renal function in normal and abnormal kidneys.

13:30         4686.     Contrast-Enhanced Kidney MRI at 7Tesla: Initial Results

Lale Umutlu¹, Stephan Orzada², Sonja Kinner, Stefan Maderwald², Irina Brote², Andreas K. Bitz², Oliver Kraff², Susanne C. Ladd², Gerald Antoch, Mark E. Ladd², Harald H. Quick², Thomas C. Lauenstein

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

Aim of this study was to assess the feasibility of contrast-enhanced kidney MRI at 7T. 8 healthy subjects were examined at a 7T whole-body MR system utilizing a custom-built 8-channel RF transmit/receive body coil. Qualitative analysis showed best overall image quality for T1w 2D FLASH imaging and strongest artifact impairment for T2w TSE imaging. Quantitative analysis showed continuous increase of SNR after iv. Gadolinium administration on T1w images and best corticomedullar differentiation in the arterial phase. This first attempt of 7T kidney imaging reveals the diagnostic potential, but also challenges of 7T abdominal MRI.

14:00         4687.     Renal Angiomyolipoma Fat Content Estimated on Pretreatment MRI as a Predictor of Response to Embolization

Joseph Abrams¹, Timothy W. Clark¹, Rahmin A. Rabenou², Hersh Chandarana¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States; ²Nephrology, NYU Langone Medical Center, New York, NY, United States

Transarterial embolization prevents hemorrhage of renal angiomyolipoma (AML) by decreasing the tumor’s angiogenic component. Our aim was to determine whether baseline AML lipid content, as estimated by AML-to-psoas signal ratio on T1 fat-saturated non-contrast acquisition, could help predict embolization response, as measured by changes in volume and enhancement on gadolinium contrast enhanced MRI (CE-MRI). Moderately good correlations were seen between baseline lipid content and change in volume and change in enhancement. These results suggest that AMLs with higher fatty components, as determined on MRI, are less likely to respond to embolization.

14:30         4688.     MRI Characterization of Liver Involvement in Autosomal-Dominant Polycystic Kidney Disease

Wei Zhang¹, Jon D. Blumenfeld², Stephanie Donahue², Honglei Zhang³, Martin R. Prince³

¹Radioloty,  Weill Cornell Medical College, new york, NY, United States; ²Internal Medicine, Weill Cornell Medical Center and The Rogosin Institute, new york, NY, United States; ³Radioloty, Weill Cornell Medical College, new york, NY, United States

135 ADPKD patients underwent abdominal MRI using a body array coil. Organ volumes and cyst volumes were measured on T2 images.RESULTS: There is significant correlation between HV and HCV, HV and HCF, HV and SPV, HCF and age, HCF and GFR, HCF and Sex, HCF and BRV, HCF and BECV, BRV and BCV at P=0.01 level. Hepatic cyst fraction  was significantly higher in female.Discussion and Conclusion:Our research prove that hepatic cysts in ADPKD are more prevalent in women than men, and women experience a larger burden of hepatic cysts than men in a younger age, implicating gender-specific hormones works in the pathogenesis of hepatic cyst involvement in ADPKD.

15:00         4689.     Intra-Observer and Inter-Observer Variability of Renal Volume Measurements in Polycystic Kidney Disease Utilizing a Semi-Automated MR Segmentation Algorithm with HASTE and TrueFISP Sequences

Benjamin A. Cohen¹, Irina Barash², Danny Kim¹, Emilio Vega¹, Matthew D. Sanger¹, Michael Bloom¹, Hersh Chandarana¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States; ²Nephrology, NYU Langone Medical Center

In Polycystic Kidney Disease (PKD), total renal volume and changes in kidney volume have been identified as sensitive markers of disease progression and, perhaps, response to future novel therapeutics.  The aim of this study was to assess the intra-observer and inter-observer variability of a semi-automated MR renal volumetric algorithm in PKD employing fluid sensitive pulse sequences emphasizing cyst conspicuity, specifically HASTE and TrueFISP.  This algorithm provided excellent intra-observer (median agreement greater than 97-98%) and very good inter-observer (median agreement greater than 93%) reproducibility.  Automated techniques, in development, will hopefully decrease inter-observer variability and processing time to support longitudinal analysis.

13:30         4690.     Sodium MR Imaging of Kidney and Other Abdominal Organs Using a Dual-Tuned Body RF Coil at 7T - not available

Kyongtae Ty Bae¹, Jung-Hwan Kim¹, Chan Hong Moon¹, Alessandro Furlan¹, Bumwoo Park¹, Tiejun Zhao²

¹University of Pittsburgh, Pittsburgh, PA, United States; ²MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States

We performed dual-tuned 23Na/1H MR imaging of human abdominal organs at 7T and demonstrated the spatial distribution of sodium in the kidney using sodium MR imaging. Future development of 23Na MR imaging will be focused on clinical application of sodium MR imaging in the abdomen to assess a variety of physiological and pathological conditions accompanied with changes in sodium concentration.

14:00         4691.     Quantitative Evaluation of Acute Renal Transplant Dysfunction with Low-Dose 3D MR Renography

Akira Yamamoto¹, Jeff Lei Zhang¹, Henry Rusinek¹, Hersh Chandarana¹, James Babb¹, Thomas Diflo², Devon John², Judith Benstein³, Pierre H. Vivier¹, David Stoffel¹, Vivian S. Lee¹

¹Radiology, New York University School of Medicine, New York, United States; ²Surgery, New York University School of Medicine, New York, United States; ³Medicine, New York University School of Medicine, New York, United States

60 patients (31 clinically normal-functioning transplanted kidney, 29 acute dysfunction transplanted kidney) were examined to assess quantitative low-dose 3D MR renography to diagnose acute transplant dysfunction. Acute rejection showed higher ratio of vascular mean transit time to whole kidney (MTT-A/K) and lower tubular transit time fraction (MTT-T/K) compared to ATN. In particular, the diagnostic test that classified patients as acute rejection when MTT-A/K 9.0% and as ATN otherwise achieved 100% diagnostic accuracy. Our method of MR renography is promising for the diagnosis of acute transplant renal dysfunction and can be performed as a component of routine anatomic imaging of the transplanted kidney.

14:30         4692.     Evaluation of the Feasibility and Reproducibility of Renal DTI MRI in Healthy Volunteers

Marica Cutajar¹, Stephen D. Marks¹, Jonathan D. Clayden¹, Christopher A. Clark¹, Isky Gordon¹

¹Radiology and Physics, UCL Institute of Child Health, London, United Kingdom

The aim of this study was to determine the reproducibility and robustness of Diffusion Tensor Imaging (DTI) in the kidney, to in turn justify the utility of this method in the clinical environment. DTI provides structural parameters relatively unstudied in kidney, the Apparent Diffusion Coefficient (ADC) and the Fractional Anisotropy (FA). The ADC gives an indication of the overall extent of diffusion, while the FA characterises the directionality of water diffusion in the tissue of interest. Initial studies have found a clear difference between the renal cortex and medulla for both ADC and FA values and both parameters were reproducible.

15:00         4693.     Renal Blood Flow Changes in Autosomal-Dominant Polycystic Kidney Disease

Wei Zhang¹, Jon D. Blumenfeld², Stephanie Donahue², Honglei Zhang¹, Martin R. Prince¹

¹Radiology, Weill Cornell Medical College, new york, NY, United States; ²Internal Medicine, Weill Cornell Medical Center and The Rogosin Institute, new york, NY, United States

Purpose:  To assess how renal blood flow changes in autosomal-dominant polycystic kidney disease (ADPKD) and its correlation with renal parenchymal volume and function.Methods: 41 ADPKD patients underwent MRA of the renal arteries using 2D cine Phase Contrast besides routine abdominal MRI.Results: GFR to both kidneys correlated directly with total blood flow.Conclusion:Our research suggest that measuring total flow to bilateral kidneys may represent an effective way to monitor renal function in ADPKD patients.

NSF & Body Diffusion

14:00         4694.     Comparative Stability of Nonionic Linear and Ionic Macrocyclic Gadolinium Chelates in Renally-Impaired Rats

Jean-Marc Idée¹, Nathalie Fretellier¹, Anne Dencausse¹, Nicolas Poveda¹, Gaëlle Jestin¹, Claire Hollenbeck¹, Marc Port¹, Jean-Sébastien Raynaud¹, Philippe Robert¹, Claire Corot¹

¹Research, Guerbet, Roissy-Charles de Gaulle cedex, France

In rats with subtotal nephrectomy receiving single injections (2.5 mmol/kg) of gadodiamide (Omniscan) for 5 consecutive days, 62 +15% of the total plasma gadolinium concentration measured at sacrifice was found to be free while the free Gd3+ concentration in plasma was < limit of detection for gadoterate (Dotarem). Relaxometry study of the skin and the bone indicate gradual  in vivo dechelation and release of free Gd3+ in rats receiving the linear GC gadodiamide (increase in the r1 relaxivity constant over time in the skin and higher r1 value vs. ex vivo matrix in skin and bone), while gadoterate remained stable.

14:30         4695.     Hyperphosphataemia Reveals Skin Lesions in Gadodiamide-Treated Rats with Low Renal Function

Jean-Marc Idée¹, Nathalie Fretellier¹, Sylviane Guerret², Marie-Christine De Goltstein¹, Anne Dencausse¹, Nicolas Poveda¹, Claire Hollenbeck¹, Walter Gonzalez¹, Cécile Factor¹, Claire Corot¹

¹Research, Guerbet, Roissy-Charles de Gaulle cedex, France; ²Novotec, Lyon, France

Rats with subtotal nephrectomy received a normal or high-phosphate diet and were allocated to single injections of 2.5 mmol/kg of gadodiamide (Omniscan) or saline for 5 consecutive days. Hyperphosphataemia enhanced histological lesions (increase in dermal cellularity, abnormalities in dermal collagen fibres and TGF-beta-1 immunostaining) and revealed macroscopic skin lesions. In the gadodiamide + high phosphate diet group, the total plasma gadolinium concentration was higher in the rats  with skin lesions than in the rats without lesions as well as the free Gd3+ concentration.

15:00         4696.     Mortality and Frequency of Nephrogenic Systemic Fibrosis

Giles Roditi¹, Tara Collidge², Peter Thomson², Jamie Traynor², Patrick Mark³, Scott Morris², Keith Simpson²

¹Radiology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ²Nephrology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ³Nephrology, Western Infirmary Glasgow, Glasgow, Scotland, United Kingdom

Nephrogenic systemic fibrosis (NSF) mortality was compared to a matched renal replacement therapy (RRT) population.  Records searched with NSF and GBCA exposure identified and onset of RRT with survival to death or census.  1826 patients with RRT,  1812 with outcome data.  Total 17 cases of NSF.  Survival for GBCA exposed and NSF cohort measured by RRT onset or post scan survival not significantly different between these groups.  Frequency of NSF cases over years studied follows the number of CE-MRA scans performed suggesting GBCA exposure causally implicated in development of NSF

15:30         4697.     A Retrospective Analysis of Nephrogenic Systemic Fibrosis in a Population Undergoing Renal Magnetic Resonance Angiography Stratified by EGFR

Giles Roditi¹, Tara Collidge², Peter Thomson², Keith Simpson², Scott Morris², Brown Michaela², Anirudh Rao²

¹Radiology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ²Nephrology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom

NSF associates with the administration of gadolinium contrast in renal impairment. Of 481 patients who underwent renal CE-MRA 3 patients were identified as having NSF. 2 had AKI when imaged, third had deteriorating CKD (eGFR 16.1) and developed NSF three years later when on dialysis following further CE-MRA. All cases of gadodiamide-associated NSF from our unit (n=16)  13 were established on dialysis, 2 had AKI and one had eGFR of 8.3 ml/min. All patients developing NSF have AKI or stage 5 CKD, we found no NSF cases with an eGFR >15 ml/min.

13:30         4698.     Renal Cell Carcinoma: 3.0-T Diffusion-Weighted MR Imaging for Subtypes Differentiation

Haiyi Wang¹, Aitao Guo², Dianjun Wang², Yuangui Gao¹, Xu Zhang³, Huiyi Ye¹

¹Radiology, PLA General Hospital, Beijing, China; ²Pathology, PLA General Hospital, Beijing, China; ³Urology, PLA General Hospital, Beijing, China

Renal cell carcinoma (RCC) is the most common malignant renal tumor in adults, with the three major subtypes, clear cell RCC, papillary RCC, and chromophobe RCC. Because of clincal needs for RCC subtypes differentiation, this study explores the ADC values of pathologically-proved clear cell, papillary, and chromophobe RCC subtypes, and  the conclusion is drawn that they possess different diffusion characteristics that can be distinguished using DWI on the basis of the ADC, with high sensitivity and specificity, potentially improving the accuracy of pretreatment diagnosis and selection of clinical therapy.

14:00         4699.     Evaluation of 3.0T MR Diffusion-Weighted Imaging in Diagnosis and Short-Term Therapeutic Effect of Renal Clear Cell Carcinoma

Xiao-duo Yu¹, Meng Lin¹, Han Ouyang¹

¹Department of Diagnostic Imaging, Cancer Hospital,Peking Union Medical College,Chinese Academy of Sciences, Beijing, China

DWI and ADC value in 3.0T MRI has widely used in tumor, but applied to clinical practice limitedly for overlap between benign and malignant tumor. 51 cases with renal clear cell carcinoma proved by operation were studied. Set ADC value at 1.8×10-3mm²/s to divide the cohort into two groups. Significant differences were found between histological grade, clinical stage. After follow-up more than one year, tumor short-term control rate of the group with ADC value more than and equal to 1.8×10-3mm²/s was better than that of the group with ADC value less than 1.8×10-3mm²/s.Therefore DWI and ADC value help to evaluate prognosis potentially.

14:30         4700.     Diffusion Weighted Imaging with Biexponential Analysis of Intravoxel Incoherent Motion in Assessment of Renal Lesions: Preliminary Experience

Hersh Chandarana¹, Vivian S. Lee¹, Elizabeth Hecht^1,2, Bachir Taouli^1,3, Eric E. Sigmund¹

¹Radiology, NYU Langone Medical Center, New York, NY, United States; ²Radiology, University of Pennsylvania, United States; ³Radiology, Mount Sinai Medical Center, New York, NY, United States

Movement of blood in microvasculature can be modeled as pseudo-diffusion also known as intravoxel incoherent motion. Perfusion effect can be separated if diffusion imaging is performed with low and high b values. The purpose of our study was to calculate perfusion fraction (fp) and tissue diffusivity (Dt) parameters obtained with biexponential analysis of multi-b DWI and determine if these parameters can distinguish enhancing from non-enhancing renal lesions. fp was higher and Dt lower in enhancing renal lesions; both these parameters had higher accuracy in detection of enhancing renal lesion compared to apparent diffusion coefficient (ADC) obtained with monoexponential fit.

15:00         4701.     Loss of Renal Diffusion Anisotropy in Patients with Chronic Kidney Disease

Yu-Chun Lin^1,2, Koon-Kwan Ng¹, Tzung-Hai Yen³, Yu-Min Chen³, Hsiang-Yang Ma², Jiun-Jie Wang⁴

¹Department of Diagnostic Radiology, ChangGung Memorial Hospital, KweiShan, Taoyuan, Taiwan; ²Department of Electrical Engineering, ChangGung University, KweiShan, Taoyuan, Taiwan; ³Department of Nephrology, ChangGung Memorial Hospital, Taiwan; ⁴Department of Medical Imaging and Radiological Science, ChangGung University, KweiShan, Taoyuan, Taiwan

Diffusion Tensor Imaging in kidney for patients with chronic kidney disease indicated a significant reduction of diffusion anisotropy. Images from 6 CKD patients and 6 normal subjects were acquired in a 3 Tesla MR scanner. Regions of interest were located bilaterally in medulla and cortex. The results showed decreases in diffusion anisotropy and associated increase in radial diffusivity, noticeably in medulla in patients. We concluded that renal DTI is feasible in 3T MR scanner and furthermore, sensitive to changes in diffusivities in patients with chronic kidney disease.

13:30         4702.     Whole-Body MRI, Including Diffusion-Weighted Imaging, for Staging Malignant Lymphoma: Direct Comparison to CT

Thomas Kwee¹, Malou Vermoolen¹, Erik Akkerman², Henriëtte Quarles van Ufford¹, Frederik Beek¹, Inge Ludwig³, Marc Bierings⁴, Rob Fijnheer⁵, Marie-José Kersten⁶, Joseph Zsiros⁷, Willem Mali¹, Rutger-Jan Nievelstein¹

¹Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ²Department of Radiology, Academic Medical Center, Amsterdam, Netherlands; ³Department of Hematology, University Medical Center Utrecht, Utrecht, Netherlands; ⁴Department of Pediatric Hematology, University Medical Center Utrecht, Utrecht, Netherlands; ⁵Department of Hematology, Meander Medical Center, Amersfoort, Netherlands; ⁶Department of Hematology, Academic Medical Center, Amsterdam, Netherlands; ⁷Department of Pediatric Hematology, Academic Medical Center, Amsterdam, Netherlands

This study aimed to assess the equivalence of whole-body MRI, including diffusion-weighted imaging (DWI), to computed tomography (CT) for the initial staging of malignant lymphoma. To that end, 66 consecutive patients with newly diagnosed malignant lymphoma prospectively underwent whole-body MRI (T1-weighted and short inversion time inversion recovery [n=66], and DWI [n=62]) at 1.5T and CT. Whole-body MRI (both with and without DWI) was equal to staging using CT in the majority of patients, while whole-body MRI overstaging occurs more frequently than whole-body MRI understaging (relative to CT).

14:00         4703.     Contrast Edited T₂ SSFSE: A Potential Alternative to Diffusion Weighted EPI for MRI Screening

Ananth J. Madhuranthakam¹, Aya Yassin^2,3, Jean H. Brittain⁴, David C. Alsop^2,3, Neil M. Rofsky^2,3

¹MR Applied Science Lab, GE Healthcare, Boston, MA, United States; ²Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; ³Harvard Medical School, Boston, MA, United States; ⁴MR Applied Science Lab, GE Healthcare, Madison, WI, United States

MRI has gained increased attention for whole-body screening of tumor metastasis.  The commonly used sequences are STIR and DW-EPI.  However, both are SNR limited and require multiple signal averages increasing the total scan time.  In addition, DW-EPI images are also subject to distortion in larger FOVs, and are typically limited to low resolution, axial plane imaging.  The primary objective of whole-body screening is to minimize the background tissue signal while simultaneously highlighting tumor signal in a rapid acquisition.  Such a technique is presented in this work using SSFSE readout while suppressing signal from fat, fluid and blood vessels.

14:30         4704.     Assessing the Advantages of Whole Body Diffusion Tensor Imaging for Screening of Bone Metastases

Matthew David Blackledge¹, David J. Collins¹, Toni Wallace¹, Dow-Mu Koh¹, Martin O. Leach¹

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

We have demonstrated that the use of whole body DTI is feasible and practicable in the time required to obtain standard diffusion weighted whole body measurements of bone metastases without significant loss in image quality.  Furthermore it is possible to measure useful biological parameters such as fractional anisotropy which may have direct clinical relevance in detecting spinal cord compression.

15:00         4705.     ADC Measurements in the Evaluation of Lymph Nodes in Patients with Non-Hodgkin Lymphoma

Thomas Kwee¹, Inge Ludwig², Cuno Uiterwaal³, Henriëtte Quarles van Ufford¹, Marc Bierings⁴, Rob Fijnheer⁵, Taro Takahara¹, Rutger-Jan Nievelstein¹

¹Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; ²Department of Hematology, University Medical Center Utrecht, Utrecht, Netherlands; ³Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands; ⁴Department of Pediatric Hematology, University Medical Center Utrecht, Utrecht, Netherlands; ⁵Department of Hematology, Meander Medical Center, Amersfoort, Netherlands

This study aimed to investigate whether apparent diffusion coefficient (ADC) measurements allow discriminating normal lymph nodes from lymphomatous lymph nodes, and indolent lymphomas from aggressive lymphomas in patients with non-Hodgkin lymphoma (NHL). To that end, 18 healthy volunteers and 22 patients with newly diagnosed NHL (indolent: n=9; aggressive: n=13) prospectively underwent diffusion-weighted imaging at 1.5 T. Our results suggest that ADC measurements may be a highly specific method for discriminating normal lymph nodes from lymphomatous lymph nodes in patients with NHL. However, ADC measurements appear to be of no utility in differentiating indolent from aggressive lymphomas.

13:30         4706.     Optimization of the B-Sampling for Bi-Exponential Analysis of Diffusion-Weighted Imaging

Jeff Lei Zhang¹, Eric E. Sigmund¹, Hersh Chandarana¹, Henry Rusinek¹, Hua Guo¹, Pippa Storey¹, Qun Chen¹, Vivian S. Lee¹

¹Department of Radiology, New York University, New York, NY, United States

Synopsis: To improve precision of bi-exponential parameters of diffusion weighted imaging (DWI), we proposed a method for optimizing b values for DWI acquisition. Monte Carlo simulation was performed to explore whether the optimized b values would improve the bi-exponential parameters’ ability in differentiating benign and malignant renal lesions. Results showed that, using the optimized b values, the differentiability of perfusion fraction for the two types of lesions improved by 22%±7%, compared with uniformly distributed b values. The method should be applicable to DWI of any other tissues or organs where bi-exponential analysis is used.

14:00         4707.     Signal to Noise Ratio of High B-Value Diffusion Weighted Images Is Improved Using Computed Diffusion Weighted Imaging

Matthew David Blackledge¹, David J. Collins¹, Dow-Mu Koh¹, Martin O. Leach¹

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

AAn acquisition scheme optimized for computed Diffusion Weighted Imaging (cDWI) is discussed and a theoretical model for diffusion weighted image noise is presented.  It is demonstrated through theory and experimental studies that noise is reduced in calculated high b-value images compared to conventional acquired high b-value DWI using this method.

14:30         4708.     Comparison of Liver ADC Measurements Using Breath-Hold, Free Breath-Hold and Respiratory Gating Echoplanar Diffusion-Weighted Imaging Sequences Using Parallel Imaging Technique with Different Acceleration Factors

Chun-Jung Juan¹, Hing-Chiu Chang^2,3, Hsiao-Wen Chung^1,3, Chi-Hong Chu⁴, Cheng-Chieh Cheng^1,3, Su-Chin Chiu^1,3, Hui-Chu Chiu^5,6, Cheng-Hsien Hsu⁷, Cheng-Yu Chen¹, Guo-Shu Huang¹

¹Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; ²Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; ³Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; ⁴Section of General Surgery, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan; ⁵Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan; ⁶EMBA in Global Chinese Management, Department of Business Administration, College of Management, Tamkang University, Taiwan; ⁷Division of Software Design, Notebook Unit 5, Quanta Computer Inc., Taiwan

Inter-experimental comparison of the liver apparent diffusion coefficient (ADC) value remains challenging. In this study the effect of repetition time (TR) and acceleration factors on the liver ADC measurement is examined. Our study shows that free-breath method allows ADC measurement consistent with breath-hold method with the TR. The ADC values measured at a longer TR in both free-breath and respiration-triggered methods are significantly higher than breath-hold method. Our results also depict significant differences in liver ADC values when different acceleration factors are chosen. Our results highlight the important of TR and acceleration factors in liver ADC measurements for inter-experimental comparison.

15:00         4709.     Assessment of Variability of Region of Interest (ROI) Delineation on Diffusion Weighted MRI (DW-MRI) Using Manual and Semi-Automated Computer Methods

Nina Tunariu¹, James A. d'Arcy, Veronica A. Morgan¹, Michael Germuska, Catherine G. Simpkin, Sharon L. Giles², David J. Collins, Nandita M. deSouza

¹ CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom; ²CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, United Kingdom

A major challenge for implementing diffusion-weighted magnetic resonance imaging (DW-MRI) as tumour response biomarker in multicentre clinical trials is in measuring changes in individual patients reliably and reproducibly. The delineation of the region of interest (ROI) has a great impact on final reproducibility. This study compares ADC values obtained using in-house computer ROI drawing software (Diffusion View) to segment tumour with those obtained from a manual drawing technique. Computer generated ROIs have the advantage of less variability, operator independence and significant time saving and support the feasibility of use of automated DWI measurements in clinical trials.

Body Diffusion

14:00         4710.     Liver DTI of Obese Insulin Resistant Subjects with Fatty Liver Disease

Lan Lu¹, Jacob M. Haus², John P. Kirwan², Chris A. Flask^1,3

¹Department of Radiology, Case Western Reserve University, Cleveland, OH, United States; ²Department of Pathobiology, Cleveland Clinic, Cleveland, OH, United States; ³Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States

Recent studies suggest diffusion-weighted (DWI) and diffusion tensor MRI (DTI) as a promising tool in studying hepatic diseases including hepatitis and cirrhosis. Similarly, Non-Alcoholic Fatty Liver Disease (NAFLD) progresses from fatty liver (steatosis) to fibrosis (steatohepatitis), but diffusion MRI studies on NAFLD subjects are limited. In this study, we used DTI to investigate the diffusion parameters in obese, insulin resistant adults with fatty liver in comparison with healthy volunteers. Our results demonstrate diffusional changes indicative of hepatic adipocyte accumulation and not fibrosis.  Therefore, hepatic lipids can complicate the utility of DWI/DTI in the study hepatic fibrosis associated with NAFLD/NASH.

14:30         4711.     The Reproducibility of Apparent Diffusion Coefficient Measurement in Liver of Healthy Volunteers at 3.0T and 1.5T Diffusion Weighted Imaging

Jiayin Gao¹, Jinning Li¹, Zhenghan Yang¹, Yuan Fu¹, Liang Xu¹, Min Chen¹, Cheng Zhou¹

¹Radiolgical Department, Beijing Hospital, Beijing, China

The aim of this study is to evaluate the reproducibility of ADC measurement in liver of healthy volunteers at 1.5T and 3.0T MR scanner. DWI of the liver was performed in 30 healthy volunteers with both 1.5T and 3.0T MR scanner in the same day. The mean ADC value of liver was 1.57¡Á10-3 mm2/s at 1.5T, while 1.35¡Á10-3 mm2/s at 3.0T (P<0.001). The result indicates that there is significant variability of ADC measurement in hepatic parenchyma at between 1.5T and 3.0T.

15:00         4712.     Application of Diffusion Weighted Proton MRI for Evaluating Molecular Diffusion of Water and Tissue Perfusion in Diethylnitrosamine Induced Rat Liver Fibrosis

Beena George¹, Andriy Babsky¹, George E. Sandusky², Navin Bansal¹

¹Radiology, Indiana University, Indianapolis, IN, United States; ²Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN, United States

The effect of hepatic fibrosis produced by diethylnitrosamine (DEN) was examined by fat and water MRI and diffusion weighted (DW) 1H MRI, separating water molecular diffusion and tissue perfusion. DEN caused an increase in liver water MRI signal intensity but no change in fat content. Fast apparent diffusion coefficient (ADC), which represents perfusion, was lower in DEN treated fibrotic livers compared to control livers. Slow ADC, which represents molecular diffusion, was same in both groups.  Measurement of perfusion by DW 1H MRI may be a useful marker for diagnosis of liver fibrosis.

15:30         4713.     Biexponential Study in Diffusion Weighted Imaging of Liver Tumours

Jean-Luc Daire¹, Ralph Sinkus², Mathilde Wagner¹, Nathalie Haddad¹, Valérie Vilgrain¹, Bernard Van Beers¹

¹CRB3 Centre de Recherches Biomédicales Bichat-Beaujon, INSERM U773, Paris, France, Metropolitan; ²Institut Langevin, ESPCI, Paris, 75005, France, Metropolitan

The aim of this project was to prospectively evaluate a DW MR imaging sequence combined with parallel acquisition to allow the calculation of pure molecular-based (D) and perfusion related (D*, f) diffusion parameters based on IVIM theory, in liver lesions according to their enhancement behaviour on 3D gradient-echo contrast-enhanced MR sequences. We have shown that D* and f values can reflect liver lesions perfusion since hypervascular liver lesions had significantly greater D* and f values than intermediate and non hypervascular lesions. A biexponential approach might be useful for the characterization of liver lesions and the assessment of tumour response.

13:30         4714.     Value of Diffusion-Weighted MR Imaging as an Early Surrogate Parameter for the Response of Colorectal Metastases to Interstitial 192Ir-High-Dose-Rate Brachytherapy

Oliver Dudeck¹, Christian Wybranski¹, Martin Zeile¹, David Löwenthal¹, Frank Fischbach¹, Maciej Pech¹, Gero Wieners¹, Jens Ricke¹

¹Radiology and Nuclear Medicine, Otto-von-Guericke University, Magdeburg, Sachsen-Anhalt, Germany

Forty colorectal liver metastases in 30 patients were evaluated with MRI including diffusion-weighted imaging (DWI) immediately before, 2 days after and 90 days following CT- and MR-guided brachytherapy. Tumor diameter (TD) and ADC were evaluated by two radiologists. On early postprocedural MRI, mean TD sligthly incresed while mean ADC decreased significantly (p<0,001). On follow-up MRI, a decrease in mean TD correlated with an increase of mean ADC (p<0,001 both; r=-0,565). In conclusion, changes in ADC can be assessed as soon as 2 days following brachytherapy. Early ADC decrease most likely reflected cell swelling, late increase reduction of tumor cell density.

14:00         4715.     Diffusion Weighted Imaging in Differentiating Malignant from Benign Intraductal Papillary-Mucinous Neoplasm of the Pancreas - not available

Atsushi Nakamoto¹, Tonsok Kim¹, Masatoshi Hori¹, Hiromitsu Onishi¹, Takahiro Tsuboyama¹, Mitsuaki Tatsumi¹, Noboru Maeda¹, Hiroki Higashihara¹, Keigo Osuga¹, Kaname Tomoda¹

¹Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan

We retrospectively evaluated the diagnostic performance of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) value for differentiating malignant intraductal papillary-mucinous neoplasm (IPMN) of the pancreas from benign IPMN. The mean minimum ADC value of malignant IPMN was lower than that of benign IPMN (P < 0.001). Mean Az value, sensitivity, specificity and accuracy of MR imaging with DWI were higher than those of MR imaging without DWI, although differences were not significant. We conclude that DWI and measurement of minimum ADC value would be helpful for differentiating malignant IPMN form benign IPMN.

14:30         4716.     New Application Screening for Malignant Tumors Using the Lesion to Spinal Cord Ratio (LSR) in Diffusion Weighted Images

Mamoru Takahashi¹, Yasuo Takehara², Takahiro Natsume³, Norihiro Tooyama, Katsutoshi Ichijo, Harumi Sakahara², Atsushi Nozaki⁴

¹Seirei Mikatabara General Hospital, Hamamatsu, Shizuoka, Japan; ²Hamamatsu University of Medicine; ³Seirei Hamamatsu General Hospital; ⁴GE Healthcare Japan

Problem: Tumor detection based on apparent diffusion co-efficient (ADC) is not always efficient and accurate on the high b-value diffusion weighted image (DWI). Method: The signal intensity ratio between lesions and spinal cord signal (LSR) were measured on DWI. The LSR was higher in malignant tumors than in other lesions. Tumor screening application �gLSR map�h was developed based on the signal intensity ratio between the lesions and the spinal cord signal on DWI. Results: With the cut-off of 0.45 for LSR, sensitivity for malignant tumor was 100%. Using the color map, effective and robust tumor screening was feasible on DWI.

15:00         4717.     Nodal Volumetric Histographic ADC Changes Associated with Successful Chemotherapy of Adolescent and Childhood Lymphoma

Shonit Punwani¹, Alan Bainbridge¹, Stuart Taylor¹, Steven Daw², Ananth Shankar², Paul Humphries¹

¹Radiology, University College London Hospital, London, United Kingdom; ²Paediatrics, University College London Hospital, London, United Kingdom

Cellular density should decrease following successful chemotherapy of lymphomatous tissue and a corresponding rise of ADC is expected. This study investigates the extent and nature of histographic post treatment ADC changes associated with a successful treatment outcome in childhood and adolescent patients with lymphoma.

13:30         4718.     Distortion Correction of Body Diffusion Weighted Images Using Three Point-Dixon Method

Saori Mori¹, Isao Muro¹, Hisamoto Moriguchi¹, Tomohiko Horie¹, Masatoshi Honda¹, Tesuo Ogino², Makoto Obara², Yutaka Imai¹

¹Radiology, Tokai university, Isehara, Kanagawa, Japan; ²Philips Healthcare Asia Pacific, Shinagawa, Tokyo, Japan

Significant distortion can often be observed in body diffusion weighted images using single shot EPI. In this study, we demonstrate that a B0 map obtained using three point-Dixon method is useful to correct for distortion. The correlation coefficients of corrected images were increased by 0.02 or greater from those of the uncorrected images. In this method, although prescan is required, it requires about a minute and a B0 map obtained from the prescan can be applied to 50 images. This method is quite useful in practice since a B0 map created using this method enables good distortion correction.

14:00         4719.     Motion Induced Signal Non-Uniformity Correction with Asymmetric Bipolar MPG on Liver DWI

Tetsuo Ogino¹, Tomohiko Horie², Isao Muro², Marc Van Cauteren³, taro takahara⁴

¹Clinical Science , Philips Electronics Japan, LTD, Minato-ku, Tokyo, Japan; ²Tokai Univ. Hospital, Japan; ³Philips Healthcare Asia Pacific, minato-ku, Tokyo, Japan; ⁴Division of Radiology, Radiotherapy and Nuclear Medicine (RRN), University Medical Center (UMC) Utrecht, Utrecht, Netherlands

Respiratory and Cardiac motion affects DWI IQ on liver. A voxel deformation due to motion under Motion Probing Gradient(MPG) induces spin phase dispersion in a voxel and results signal loss. By replacing conventional MPG with a pair of bipolar gradient, the signal loss is reduced significantly. However, minimum TE and TR are prolonged due to low efficiency of such type of MPG. We propose a novel MPG method which is formed as hybrid of conventional MPG and bipolar MPG. Image quality of liver diffusion is significantly improved with slight scan time prolongation from conventional respiratory triggered DWI.

14:30         4720.     Comparison of Simulation-Based and Measurement-Based RF Shimming for Whole-Body MRI at 7 Tesla

Andreas K. Bitz^1,2, Irina Brote^1,2, Stephan Orzada^1,2, Oliver Kraff^1,2, Stefan Maderwald^1,2, Harald H. Quick³, Klaus Solbach⁴, Achim Bahr⁵, Hans-Peter Fautz⁶, Franz Schmitt⁶, Mark E. Ladd^1,2

¹Erwin L. Hahn Institute for MRI, University Duisburg-Essen, Essen, Germany; ²Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany; ³Institute for Medical Physics, Friedrich-Alexander-University, Erlangen-Nuernberg, Germany; ⁴High Frequency Technique, University Duisburg-Essen, Duisburg, Germany; ⁵IMST GmbH, Kamp-Lintfort, Germany; ⁶Siemens Healthcare Sector, Erlangen, Germany

The aim of this study was to compare RF shimming procedures based on RF simulations and measured B1+ maps for different ROIs in the thorax and abdomen of volunteers with varying physique. Simulation-based RF shims were computed by use of heterogeneous body models. In vivo B1+ mapping was performed during breath hold by utilization of a pre-saturation turboFLASH. ROIs in the heart, liver, and kidney were considered. Appropriate simulation-based shims could be derived which function in the majority of considered volunteers. If the numerical body model inadequately describes the subject’s body, measured shims should be preferred to achieve higher image quality.

15:00         4721.     Combinatorial Fat Suppression for Diffusion Weighted Imaging at 3.0T

Matthew David Blackledge¹, David Higgins², Dow-Mu Koh¹, Nandita M. deSouza¹, Martin O. Leach¹, David J. Collins¹

¹CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom; ²Philips Healthcare, Guildford, Surrey, United Kingdom

A variety of fat suppression techniques including STIR, SPIR, SPAIR and SSGR used alone or in combination are investigated for use in large field of view Diffusion Weighted Imaging at 3.0T.  We conclude that a combinatorial approach improves results. A combination of STIR and SPIR works well and can be further improved used in combination with SSGR. All methods would benefit from improved shimming over large field of view to reduce off-resonance attenuation effects.

13:30         4722.     DTI at Different B-Values in Kidneys in Children with Unilateral Pylonephritis

Claudia Testa¹, Laura Miglio², David Neil Manners¹, Caterina Tonon¹, Emil Malucelli¹, Bruno Barbiroli¹, Andrea Pasini², Giovanni Tani², Raffaele Lodi¹

¹MR Spectroscopy Unit, Department of Internal Medicine, Aging and Nephrology, University of Bologna, Bologna, Bo, Italy; ²Paediatric Radiology Unit, Department of Woman, Child and Adolescent Health, University of Bologna, Bologna, Italy

DTI was used to evaluate renal damage in patients with chronic pyelonephritis. In 12 children affected by unilateral pyelonephritis as assessed by renal scintigraphy (Tc99-DMSA), axial DT images were acquired at b-values of 0, 100, 300, 600, 800 s/mm2. The mean diffusivity (D) and fractional anisotropy (FA) maps were generated for each b-value. We found that FA discriminated values from cortex and medulla better than D in healthy kidneys. D and FA decreased in affected kidneys at each b-values, in particular in the cortex of kidney poles. Changes of D and FA correlated with the degree of functionality damage found by scintigraphy.

14:00         4723.     Effect of Nutritional State on IVIM Parameters Measured with Multiple B Value Diffusion MRI

Clifford R. Weiss¹, Atilla Peter Kiraly², Ralph Strecker³

¹Department of Radiology, The Johns Hopkins Univeristy School of Medicine, Baltimore, MD, United States; ²Imaging and Visualization, Siemens Corporate Research, Princeton, NJ, United States; ³MR Oncology, Siemens Healthcare, Erlangen, Germany

Existing liver diffusion MR studies have moderate variability in computed ADC values. Reasons from transient changes in portal venous flow to noise have been attributed to this variability. However, the massive increase in splanchnic/portal blood flow after eating does not seem to be taken into account. We present a study comparing diffusion data before and after fasting that shows a large increase in ADC values after eating. Although it is a small study, results suggest that patient feeding state should be factored into future studies.

14:30         4724.     High Directional Coherence in Renal Cortex as Shown in Diffusion Tensor Imaging

Ming-Cherng Wu¹, Yu-Chun Lin^1,2, Chung-Huang Hsieh¹, YauYau Wai^1,3, JiunJie Wang^1,3

¹Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, LinKou, Tao Yuan, Taiwan, Taiwan; ²Department of Electrical Engineering, Chang Gung University; ³Department of Medical Imaging and Radiological Sciences, ChangGung University

Renal cortex is the part of renal columns that contain the renal corpuscles and the renal tubules. The direction of water diffusion is consistent, which was properly reflected in the map of InterVoxel Diffusion Coherence. Diffusion Tensor Imaging in kidney were acquired from a 3T scanner. InterVoxel Diffusion Coherence detected high uniformity of the eigenvector distribution in the renal cortex. In the other hand, low Fractional Anisotropy in the corresponding regions suggested diffusion isotropy within cortex.

MRS - Body Applications

14:00         4725.     ¹H-MRS Links Adipose Tissue Fat Composition to Liver Fat Content in Men with Metabolic Syndrome

Jesper Lundbom¹, Antti Hakkarainen¹, Sanni Söderlund², Nina Lundbom¹, Marja-Riitta Taskinen²

¹HUS Medical Imaging Centre, University of Helsinki, Helsinki, Finland; ²Department of Medicine, University of Helsinki

We used 1H-MRS to study adipose tissue fat composition and liver fat content in men with the metabolic syndrome. Adipose tissue methylene/methyl, an index of saturated fats, correlated negatively with liver fat content.

14:30         4726.     In-Vivo Determination of the Full¹H MR Spectrum of Liver Fat

Gavin Hamilton¹, Michael S. Middleton¹, Takeshi Yokoo¹, Mark Bydder¹, Irene W. Mwangi¹, Michael E. Schroeder¹, Claude B. Sirlin¹

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

Accurate proton (¹H) MRS fat quantification of liver fat requires determination of signal from fat peaks that are near or under the water peak. A theoretical triglyceride model was developed to characterize the liver fat spectrum, using number of -CH=CH- and -CH=CH-CH₂-CH=CH- bonds, and average fatty acid chain length. In vivo, the relative areas of the different fat peaks are strongly correlated suggesting the fat profile is uniform regardless of the level of fat deposition in the liver.  The model gives that 8.6% of the total liver fat underlies the water peak.

15:00         4727.     Comparison of Liver Steatosis Quantification by MRS at 4.7 T and Histology on Ob/ob and Db/db Mice - not available

Fanny Noury^1,2, Alain Fautrel^3,4, Eric Hitti^1,2, Pascale Bellaud³, Hervé Saint-Jalmes^1,2, Bernard Fromenty⁴, Pierre-Antoine Eliat²

¹LTSI - INSERM U642 -  Université Rennes 1, Rennes, France; ²PRISM - IFR 140 BiogenOuest - Université Rennes 1, Rennes, France; ³Plate-forme d’Histopathologie - IFR 140 BiogenOuest - Université Rennes 1, Rennes, France; ⁴FMC - INSERM U991 - IFR 140 - Université Rennes 1, Rennes, France

Murine models of obesity such as ob/ob (leptin deficient) and db/db (leptin receptor deficient) mice are extensively used in different scientific fields including pharmacology and toxicology. Besides increased body fatness, hyperlipidemia and insulin resistance these mice develop moderate (db/db) or massive (ob/ob) steatosis. In some studies a longitudinal follow-up of steatosis may be warranted, to assess the beneficial (or deleterious) effects of chronic drug administration. In this preliminary study, db/db and ob/ob mice were used to determine whether magnetic resonance spectroscopy could be a reliable non-invasive method to evaluate fatty liver, using statistical comparison with histological results.

15:30         4728.     Validation of ¹H Magnetic Resonance Spectroscopy (¹H-MRS) for Quantification of Hepatic Triglyceride Content

Estee Fleischman¹, Lauren Dutcher¹, David Thomasson², Adeline Louie², Haresh Mani³, David Kleiner³, Caryn Morse¹, Colleen Hadigan¹

¹National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States; ²Diagnostic Radiology Department, National Institutes of Health, Bethesda, MD, United States; ³National Cancer Institute, National Institutes of Health, Bethesda, MD, United States

There is growing interest in the application of 1H-MRS as a non-invasive approach to quantify hepatic triglyceride.  This study was designed to establish the ability of 1H-MRS to accurately assess hepatic fat compared to histological scoring. Fifty subjects completed 1H-MRS of the liver within 30 days of diagnostic biopsy.  The mean hepatic triglyceride content by 1H-MRS for each histologic grade was 9%, 23%, 40% and 56%, respectively.  The correlation between the two methods was r=0.88, p<0.0001. With the phantom data we achieved an r=0.98 (p=0.02) over a range of fat-water fractions of 10 to 20 % using the standardized formula.

13:30         4729.     A Simple Approach for Improving Lipid SNR for Hepatic Fat Measurement with 1H MRS

Giulio Gambarota¹, Mark Tanner¹, Johanna Berg², Robert V. Mulkern³, Rex D. Newbould¹

¹GlaxoSmithKline, London, United Kingdom; ²Radiology, University Hospital of Malmö, Sweden; ³Radiology, Children's Hospital Boston, Boston, MA, United States

Magnetic resonance spectroscopy (MRS) is becoming the method of choice for non-invasive assessment of lipids in liver. To avoid artifacts due to liver motion, MRS is often performed with a breath-hold approach. Given the limited amount of time available to perform the acquisition, it is of interest to maximize the signal-to-noise ratio (SNR) of the lipid resonances. Here, we show that it is possible to substantially improve the SNR of the in liver, by choosing an appropriate TR. The current approach has the advantage of experimental simplicity and can be applied to all basic sequences routinely used in clinical settings.

14:00         4730.     Proton MRS of Changes of Lipid Unsaturation During Liver Regeneration

Kannie W. Y. Chan^1,2, April M. Chow^1,2, Shu Juan Fan^1,2, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China

Post-operative diagnosis is important in partial hepatectomy (PHx) to determine the best time for interventions or therapeutic measures. We studied changes in unsaturated lipids verse saturated lipids as a mean to follow liver regeneration. The amount of unsaturated lipid at different time points showed a related trend with liver regeneration. A high level was found at 24h post-PHx, and was correlated with the maximum liver regeneration, and the saturated lipid stayed at a high level during the first day of regeneration. Thus, this pilot study shows that 1H-MRS could provide us with more information on the degree of regeneration.

14:30         4731.     The Effect of Meal and Exercise on the in Vivo 31P-NMR Liver Spectrum: Initial Findings - not available

Antti Hakkarainen¹, Jesper Lundbom^1,2, Esa K.J. Tuominen¹, Marja-Riitta Taskinen, Kirsi Hannele Pietiläinen³, Nina Lundbom¹

¹Helsinki Medical Imaging Centre, University of Helsinki, Helsinki, Finland; ²Department of Medicine, Division of Cardiology, University of Helsinki, Helsinki, Finland; ³Obesity Research Unit, Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland

We studied the effects of a normal high-fat meal and subsequent exercise on the 31P MR spectrum of healthy volunteers using a proton-decoupled 31P MR spectroscopy at 3 T. We found a trend of rising ATP resonance at postprandial state suggesting that the physiological state may have an impact and should be standardized in phosphorus studies.

15:00         4732.     Reproducibility Evaluation of Spatially Resolved Liver ³¹P Metabolism Using a Dual Tuned 8-Channel ³¹P/¹H Coil

Anshuman Panda^1,2, Scott Ray Jones^1,2, Ulrike Dydak^1,2

¹School of Health Sciences, Purdue University, West Lafayette, IN, United States; ²Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States

Regional changes in the ³¹P metabolite concentration of the whole liver can be acquired using a multi-channel phased-array ³¹P coil. However, changes in coil placement, separation between anterior and posterior coil, and spectroscopic imaging setup can significantly affect the reproducibility of the data. Methods to maximize data reproducibility including reproducible coil placement and spectroscopic planning, correction of coil sensitivities, and evaluation of the data variability from one scan to another for a whole liver ³¹P 2D MRSI experiment is presented for a dual tuned 8-channel ³¹P/¹H coil.

13:30         4733.     In Vivo Proton MRS of Liver in an Experimental Liver Fibrosis Model

Jerry S. Cheung^1,2, Shu Juan Fan^1,2, Darwin Shan Gao^1,2, Kannie W.Y. Chan^1,2, April M. Chow^1,2, Kwan Man³, Ed X. Wu^1,2

¹Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ³Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong SAR, China

Carbon tetrachloride (CCl₄) intoxication is a well-characterized, reproducible and the most commonly used experimental model of liver fibrosis. Proton magnetic resonance spectroscopy (¹H MRS) can provide insights into in vivo liver metabolism noninvasively, yet detailed in vivo MRS study of CCl₄-induced liver fibrosis model has been limited. The aim of this study was to characterize early metabolic changes in CCl₄-induced liver fibrosis in rodents by means of single-voxel ¹H MRS. Our experimental results demonstrated that ¹H MRS at high field may be valuable in characterizing metabolic changes in liver, in particular those related to lipid and glutamine metabolism, after CCl₄ insult.

14:00         4734.     Can Localised 19F MRS Pharmacokinetics of 5FU in Colorectal Metastases Predict Clinical Response?

Dominick John McIntyre¹, Franklyn Arron Howe², Christophe Ladroue², Fiona Lofts², Marion Stubbs¹, John Richard Griffiths¹

¹CRUK Cambridge Research Institute, Li Ka Shing Centre, Cambridge, United Kingdom; ²St George's, University of London, United Kingdom

We have applied 19F MRS to measure the pharmacokinetics of 5FU metabolism in the livers of 32 patients with colorectal cancer. 15 of the subjects had liver metastases. 5FU half-lives ranged from 4 to 15 minutes and were not significantly different between patients with and without liver metastases. In the group with metastases, high levels of toxic fluoronucleotides, primarily produced in tumour cells, were associated with poorer survival. This may be due to higher metastatic load giving higher concentrations of fluoronucleotides and poorer survival.

14:30         4735.     Proton Magnetic Resonance Spectroscopy (¹H-MRS) of Adrenal Gland Masses Using a Multiple Array Coil (32 Channels) at 1.5T

Aude Fregeville¹, Stephane Silvera¹, Lionel Groussin², Olivier Vignaux¹, Victoria Cavero Machado³, Nashiely Pineda Alonso³, Paul Legmann¹

¹Department of Radiology, University René Descartes Paris V, Hôpital Cochin, Paris, France; ²Service des Maladies Endocriniennes et Métaboliques, University René Descartes Paris V, Hôpital Cochin, Paris, France; ³Siemens Healthcare, Paris, France

A size up to 3 cm lesion in the adrenal glands leads the patient to surgery. MRS is a promising tool for the classification of adrenal masses. We evaluated the advantages of multiple channel phased array (32-channel) coil in the respiratory-triggered proton single-voxel MR spectroscopy technique at 1.5 T for the diagnosis of adrenal masses and the differentiation between them. The gain in signal of the 32 channel coil gave an excellent spectral quality even in a free breathing acquisition at 1.5 Tesla. It is possible in deed to differentiate the types of masses by their spectral characteristics and  ratios.

15:00         4736.     Can Regurgitation of Pancreatic Juice Into the Biliary Tract Be Detected by ¹H MR Spectroscopy?

Omkar B. Ijare¹, Tedros Bezabeh¹, Nils Albiin², Annika Bergquist², Urban Arnelo², Mathias Lohr², Espen Melum³, Ian C.P. Smith¹

¹National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden; ³Deparment of Medicine, Oslo University Hospital, Oslo, Norway

Regurgitation of pancreatic juice into the biliary tract and the subsequent mixing with bile is frequently observed in patients with pancreaticobiliary maljunction (PBM), which is a potential risk factor for the carcinogenesis of bile duct and gallbladder. The mixing of bile with pancreatic juice is generally diagnosed by measuring the amylase activity in bile. We propose that pancreaticobiliary reflux can be detected by ¹H MR spectroscopy as an alternative to the measurement of amylase activity. Moreover, it may be possible to detect non-invasively the regurgitation of pancreatic fluids into the gallbladder using  in vivo spectroscopy.

Renal & Prostate

13:30         4737.     MR Voiding Cystourethrography (MRVC) for Vesicoureteric Reflux in Unsedated Infants

Owen John Arthurs¹, Ilse Joubert¹, Martin John Graves¹, Pat Set¹, David John Lomas¹

¹Department of Radiology, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

Vesico-ureteric reflux is a congenital disorder of the paediatric renal tract, for which the current gold standard is the Micturating Cystourethrogram (MCUG). This study evaluated the feasibility of MR voiding cystourethrography using dilute intravesical gadolinium in unsedated infants. Real time interactive switching between gradient echo (SPGR) and SSFSE based pulse sequences allowed 6 children with urinary tract abnormalities to undergo both MCUG and MRI. There was 83% concordance between MCUG and MRVC regarding vesicoureteric reflux, and complete agreement regarding the urethra and bladder. Fluoroscopic MR assessment of the complete paediatric renal tract is possible in unsedated infants.

14:00         4738.     Carr-Purcell-Meibom-Gill T2 Mapping of Prostate at 3 T.

Giulio Gambarota¹, R L. Janiczek¹, Robert V. Mulkern², Rex D. Newbould¹, Brandon Whitcher¹

¹GlaxoSmithKline Clinical Imaging Center, London, United Kingdom; ²Radiology, Children's Hospital Boston, Boston, United States

In clinical MR examinations of the prostate, a multiparametric approach (T1- and T2-weighted images, quantitative measurement of the apparent diffusion coefficient (ADC) of water, dynamic contrast-enhanced MRI) is becoming standard procedure.  The Carr-Purcell-Meiboom-Gill (CPMG) approach has recently been proposed for T2 mapping of the prostate at 1.5 T. No such studies have been performed at 3 T. Translating the CPMG sequence to 3 T is not straightforward and involves compromises in clinical implementation. Here we have shown high quality measurements of T2 may be obtained over the entire prostate by careful design of the clinical acquisition.

14:30         4739.     Ultra Short Gradient Echo Imaging of the Prostate at 7T - not available

Gregory John Metzger¹, Steen Moeller¹, Patrick J. Bolan¹, Eddie J. Auerbach¹, Jang-Yeon Park¹, Michael Garwood¹

¹Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

The purpose of this study was to investigate the potential of an ultra-short TE 3D radial sequence, for imaging the prostate at 7T. This technique is desirable for DCE-MRI because it would greatly reduce both the large T2* effect of paramagnetic contrast agents at high field, and the inflow artifacts that can bias the measurement of the arterial input function. Furthermore the sequence gives spatially isotropic resolution and, when combined with sparse temporal sampling methods, can provide very high temporal resolution.  This work demonstrates the feasibility and imaging quality of this technique and discusses its strengths and weaknesses.

15:00         4740.     Histopathological Composition of Prostate Tissues and Their Impact on DCE MRI Measures

Susan M. Noworolski^1,2, Kyle Kuchinsky³, Michelle Nystrom¹, John Kurhanewicz^1,2, Daniel B. Vigneron^1,2, Peter R. Carroll⁴, Kirsten Greene⁴, Jeffry Simko³

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; ³Pathology, University of California, San Francisco, CA, United States; ⁴Urology, University of California, San Francisco, CA, United States

Validation of MR measures of the prostate are challenging due to heterogeneity. Tissue compositions by histopathology and their impact on DCE MRI measures were evaluated and compared in high and moderate grade prostate cancers. Fourteen men had DCE MRI before prostatectomy. High Gleason Grade (≥4+4) lesions had higher %cancer than Gleason 3+3 lesions (87% vs. 58%, p<0.00001). Normalizing DCE MRI measures to %cancer led to higher measures versus healthy peripheral tissues and greater separations between 3+3 and 4+4 cancers. Heterogeneity of tissues and %cancer may impact DCE MRI measures, with potentially different effects in Gleason Grade 3+3 versus 4+4 cancers.