Lucian A. B. Purvis¹, William T. Clarke¹, Michael Pavlides¹, Stefan Neubauer¹, Matthew D. Robson¹, and Christopher T. Rodgers^1
1Department of Cardiovascular Medicine, University of Oxford, Oxford, Oxfordshire, United Kingdom

Using a 16-element receive array at 7T permitted precise quantification of ³¹P metabolite ratios from the whole liver, in a study on 5 normal volunteers. A 3D UTE-CSI sequence gave an average of 27 voxels (each 6.3mL nominal volume) of high quality data for each subject. The inter-subject mean and SD of the metabolite ratios (averaged over all voxels) were then calculated: 36.4 ± 6.94 for PME/PDE, 44.4 ± 3.93 for GPC/Total Ester and 12.6 ± 3.58 for PE/Total Ester. This preliminary work will inform the design of future clinical studies of diseases such as non-alcoholic fatty liver disease.

Peter Bannas^1,2, Candice A Bookwalter¹, Tim Ziemlewicz¹, Utaroh Motosugi¹, Richard Bruce¹, Theodora A Potretzke¹, and Scott B Reeder^1,3
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ³Medical Physics, University of Wisconsin-Madison, WI, United States

On gadoxetic acid enhanced hepatobiliary-phase MRI it can be challenging to detect small and/or perivascular focal liver metastases. Moreover, both metastases and benign cavernous hemangiomas appear hypointense and may be difficult to distinguish from one another. In this study we compared hepatobiliary phase MRI for detection and characterization of liver lesions by using an intravascular gadolinium based contrast agent, gadofosveset trisodium, in addition to gadoxetic acid in 78 patients with suspected metastases or hemangiomas. Our results revealed that combined gadoxetic acid and gadofosveset enhanced liver MRI improves liver lesion detection and characterization when compared to gadoxetic acid alone.

Navin Michael¹, Suresh Anand Sadananthan¹, Jadegoud Yaligar², Swee Shean Lee², Melvin Khee-Shing Leow^1,3, Chin Meng Khoo⁴, Eric Yin Hao Khoo⁴, Kavita Venkataraman⁵, Yung Seng Lee^1,6, Yap Seng Chong^1,7, Peter D. Gluckman¹, E. Shyong Tai⁴, and S. Sendhil Velan^2,8
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, ²Singapore BioImaging Consortium, A*STAR, Singapore, ³Department of Endocrinology, Tan Tock Seng Hospital, Singapore, ⁴Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, ⁵Saw Swee Hock School of Public Health, National University of Singapore, Singapore, ⁶Department of Paediatrics, Yong Loo Lin School of Medicine, Singapore, ⁷Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, Singapore, ⁸Clinical Imaging Research Centre, A*STAR, Singapore

The ability to measure adipose hypertrophy in vivo is relevant to better understand the pathophysiology involved in type 2 diabetes. Traditionally, adipose tissue hypertrophy has been assessed directly by histological examination of adipose tissue explants which is invasive and inconvenient to carry out in large cohort studies. The current work investigates the use of adipose tissue hydration, as measured using ¹H MRS based hydrolipidic ratio, as a noninvasive marker of adipose tissue hypertrophy, and its association with serum metabolic parameters, insulin sensitivity, BMI, adipose depot volumes and ectopic fat infiltration in liver and skeletal muscle.

Deirdre M McGrath^1,2, Alejandro F Frangi¹, Iain D Wilkinson², and Zeike A Taylor^1
1CISTIB, Center for Computational Imaging & Simulation Technologies in Biomedicine, University of Sheffield, Sheffield, South Yorkshire, United Kingdom,²Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

Magnetic resonance elastography (MRE) is currently being explored as a biomarker of neurodegenerative disease including dementia. A difficulty for this process of evaluation is that the measures of biomechanical properties obtained for healthy brain using MRE have varied widely. However the methodology has not been consistent between studies, such as wave frequency and the means of wave delivery. In this work an initial evaluation of has been made of a method to simulate skull vibration dynamics during MRE, to compare the impact of delivering the waves from different positions on the skull.

Susan M Noworolski¹, Kathleen Mulligan², Natalie Korn¹, Molly Gibson¹, Viva W Tai^2,3, Michael Wen², Ayca Erkin-Cakmak⁴, Alejandro Gugliucci⁵, Robert H Lustig⁴, and Jean-Marc Schwarz^6
1Radiology & Biomedical Imaging, University of California, San Francisco, California, United States, ²Medicine, University of California, San Francisco, California, United States, ³CTSI-CRS, University of California, San Francisco, California, United States, ⁴Pediatrics, University of California, San Francisco, California, United States, ⁵Research, Touro University College of Osteopathic Medicine, Vallejo, California, United States, ⁶Basic Science, Touro University College of Osteopathic Medicine, Vallejo, California, United States

Thirty-six obese African American and Latino high-sugar consuming children underwent a 10-day isocaloric, fructose/sugar-restricted diet. Liver, pancreatic, visceral fat (VAT), and subcutaneous fat (SAT) were measured at baseline and 10 days later using MRS and Dixon-type imaging at 3T. The liver fat fraction decreased 29.5% ± 23% (p<0.001). Pancreatic fat fraction was lower in 74% (20/27) participants (p<0.05) with varied amounts of decrease. VAT decreased 6.9% ± 14% (p<0.006) while SAT did not change significantly. Subjects lost 1.1 ± 1.2% of body weight during the study. Decreases in MR-measured fat remained significant after adjustment for this minor weight loss.

Hatim Chafi¹, Saba N Elias², Huyen T Nguyen², Harry T Friel³, Michael V Knopp², BeiBei Guo⁴, Steven B Heymsfield⁵, and Guang Jia^1
1Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States, ²Department of Radiology, The Ohio State University, Columbus, Ohio, United States, ³Clinical Science Operations, Philips Healthcare, Highland Heights, Ohio, United States, ⁴Department of Experimental Statistics, Louisiana State University, Baton Rouge, Louisiana, United States, ⁵Metabolism - Body Composition, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States

18 prostate cancer patients underwent DCE-MRI scans on a 3T scanner) using a single channel RF transmit Q-body and 32-channel phased-array surface coils, while 21 patients were imaged on the same scanner with a parallel RF transmission upgrade. Comparison of baseline signal and signal enhancement in the left and right femoral arteries, indicates that baseline signals and signal enhancement are significantly more symmetrical. High field (3.0 T) MRI scanners equipped with multiple-channel parallel RF transmission enhances the symmetry of arterial input function in femoral arteries resulting in more consistent and homogeneous quantitative pharmacokinetic modeling in DCE-MRI of prostate cancer.

Janne West^1,2, Thobias Romu^2,3, Anna-Clara Spetz Holm⁴, Hanna Lindblom¹, Lotta Lindh-Åstrand⁴, Magnus Borga^2,3, Mats Hammar⁴, and Olof Dahlqvist Leinhard^1,2
1Department of Medical and Health Sciences, Linköping University, Linköping, Sweden, ²Center for Medical Imaging Science and Visualization, Linköping, Sweden, ³Department of Biomedical Engineering, Linköping University, Linköping, Sweden, ⁴Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden

Quantitative and exact measurements of fat and muscle in the body are important when addressing some of the greatest health-challenges today. In this study whole-body combined regional muscle and fat volume quantification was validated in a group of postmenopausal women, where the body composition is changing. Twelve subjects were scanned with a 4-echo 3D gradient-echo sequence. Water and fat image volumes were calculated using IDEAL, and image intensity correction was performed. Subsequently, automatic tissue segmentation was established using non-rigid morphon based registration. Whole-body regional fat and muscle segmentation could be performed with excellent test-retest reliability, in a single 7-minutes MR-scan.

Hui Zhang¹, Aiqi Sun¹, Xiaodong Ma¹, Zhe Zhang¹, Ed X. Wu^2,3, and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, ²Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, ³Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China

Diffusion-weighted imaging (DWI) has been increasingly used in clinical applications due to its sensitivity to microscopic motion in biologic tissue. However, the DW signal depends on not only b-value but also the diffusion time due to restricted diffusion phenomenon. This work proposed an optimized stimulated-echo (STE) DWI method and aimed to investigate the dependence of diffusion measurement on diffusion time in healthy human liver. The results show that restricted diffusion behavior is observed in human liver at 3T, which demonstrates the effect of both b-value and diffusion time on liver DWI quantification.

Noam Nissan¹, Talia Golan², Edna Furman-Haran¹, Sara Apter², Yael Inbar², Arie Ariche², Barak Bar Zakay², Yuri Goldes², Michael Schvimer², Dov Grobgeld¹, and Hadassa Degani^1
1Weizmann Institute of Science, Rehovot, Israel, ²Sheba Medical Center, Israel

The diagnostic utility of 3T abdomen-MR DTI using b-values (0,100,500) and multi-b DWI were investigated in the healthy pancreas and pancreatic adenocarcinoma. Analysis of the DTI and DWI suggested a contribution of IVIM to the diffusion coefficient of the healthy pancreas at b<100 s/mm2 leading to a significant reduction in the diffusion coefficients and increase in FA at b-values of 100-500s/mm2 compared to 0-500 s/mm2. Cancer was characterized by lower diffusion coefficients in both b-sets and a smaller difference in these coefficients between the two sets, suggesting high cellularity and decreased perfusion, compared to normal pancreatic tissue.

Thomas A Hope¹, Carina Mari Aparici¹, Eric Nakakura², Henry VanBrocklin¹, Miguel Hernandez Pampaloni¹, James Slater¹, Salma Jivan¹, Judy Yee¹, and Emily Bergsland^3
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Department of Surgery, UCSF, San Francisco, CA, United States,³Department of Medicine, UCSF, San Francisco, CA, United States

We have evaluated the combined modality PET/MRI for imaging of patients with hepatic metastasis from neuroendocrine tumor. Patients were imaged using Ga-68 labeled DOTA-TOC in conjuction with gadoxetate disodium as an MR contrast agent. Preliminary data demonstrates that PET/MRI is at least equivalent to PET/CT, with likely improved detection of hepatic lesions on hepatobiliary phase imaging.

John P. Mugler, III¹, G. Wilson Miller¹, Craig H. Meyer², Kun Qing¹, Jaime F. Mata¹, Steven Guan², Kai Ruppert^1,3, Iulian C. Ruset^4,5, F. William Hersman^4,5, and Talissa A. Altes^1
1Radiology & Medical Imaging, University of Virginia, Charlottesville, VA, United States, ²Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ³Cincinnati Children's Hospital, Cincinnati, OH, United States, ⁴Xemed, LLC, Durham, NH, United States, ⁵Physics, University of New Hampshire, Durham, NH, United States

The purpose of this work was to determine if 129Xe can be detected in human abdominal organs, such as the kidneys. Dissolved-phase 129Xe imaging was performed at 1.5T in two healthy subjects. Dissolved-phase 129Xe was seen in the kidneys of both subjects, and a linear structure, consistent with the position of the descending aorta, was seen passing between the kidneys and bifurcating below the kidneys. These results may be of interest for kidney perfusion imaging. In addition, if multiple 129Xe resonances can be detected in the kidneys, dissolved-phase 129Xe imaging may offer additional interesting information on kidney function and disease.

Maryam Seif¹, Ute Eisenberger², Tobias Binser¹, Harriet C Thoeny³, Fabienne Krauer¹, Chris Boesch¹, Bruno Vogt⁴, and Peter Vermathen^1
1Depts. Radiology and Clinical Research, University Bern, Bern, Switzerland, ²Dept. Nephrology, University Hospital Essen-Duisburg, Essen, Germany,³Dept. Radiology, Neuroradiology and Nuclear Medicine, University Hospital of Bern, Bern, Switzerland, ⁴Dept. Nephrology, Hypertension and Clinical Pharmacology, University Hospital of Bern, Bern, Switzerland

We determined renal oxygenation changes associated with uninephrectomy and transplantation in both, remaining and transplanted kidneys using blood oxygenation level-dependent (BOLD) MRI. Thirteen healthy kidney donors and their corresponding recipients underwent kidney BOLD MRI. BOLD MRI was performed in donors before uninephrectomy and in donors and recipients at day 8, month 3 and 12 after transplantation. BOLD MRI detects increased oxygen content in the remaining kidney of living kidney donors as very early adaptation to transplantation of the contralateral kidney. In contrast, the oxygen content in the transplanted kidney remains very constant.

Yi Xin¹, Maurizio Cereda², Hooman Hamedani¹, Harrilla Profka¹, Justin Clapp¹, Stephen Kadlecek¹, Brian P. Kavanagh³, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States, ³Hospital for Sick Children, Toronto, Ontario, Canada

Atelectasis and mild local lung injury cause redistribution of inspired gas to residual ventilated airspaces, resulting in their over-ventilation and potentially damaging ventilatory stress. This dynamic can be spatially evaluated by hyperpolarized 3He imaging. Hyperpolarized 3He maps of fractional ventilation (r) demonstrate that recruitment with PEEP attenuates residual over-ventilation in HCl models of circumscribed lung injury.

Fumin Guo^1,2, Sarah Svenningsen^1,3, Aaron Fenster^1,2, and Grace Parraga^1,2
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, ²Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada, ³Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

Many applications of pulmonary ¹H MRI require lung cavity segmentation as a prerequisite. Accordingly, we proposed a convex optimization based approach to simultaneously segment the right and left lungs from pulmonary ¹H MRI in 3D. Our approach employs the latest developments in convex optimization techniques and solves the original challenging optimization problem globally and exactly under the primal and dual perspective. We implemented the algorithm in a modern parallel computing platform and applied it to a clinical dataset of ten COPD subjects. Our experimental results demonstrate that this computationally efficient method yields highly accurate lung volumes with minimal user interaction.

Felix C Horn¹, Helen Marshall¹, Salman Siddiqui², Alexander Horsley³, Laurie Smith¹, Ina Aldag⁴, Richard Kay⁵, Christopher J Taylor⁴, Juan Parra-Robles¹, and Jim M Wild^1
1Sheffield University, Sheffield, United Kingdom, ²University of Leicester, United Kingdom, ³University of Manchester, United Kingdom, ⁴Sheffield Children's NHS Foundation Trust, NHS, United Kingdom, ⁵Novartis, Switzerland

Gas washout measured with hyperpolarized helium-3 MRI can be used to obtain quantitative regional lung function in 3D (MBW-I). Multiple breath inert gas washout as clinically performed in the pulmonary function lab (MBW) is sensitive to early signs of ventilation heterogeneity in obstructive lung diseases. In this work MBW-I and MBW were performed in healthy controls, CF patients and an asthma cohort. Ventilation heterogeneity as measured by MBW-I was found to correlate significantly with MBW & spirometry. The MBW-I derived parameter to measure ventilation heterogeneity was found to be more sensitive to ventilation heterogeneity than conventional MBW and spirometry.