ISMRM 25th Annual Meeting & Exhibition • 22-27 April 2017 • Honolulu, HI, USA

Scientific Session: Novel Abdominal Applications & Developments

Body: Breast, Chest, Abdomen, Pelvis

Thursday, 27 April 2017
Room 313A  15:30 - 17:30 Moderators:  Houchun Hu, ChangHee Lee

Slack Channel: #s_body
Session Number: O28


Probing bone marrow adipocyte cell size in vivo at a clinical 3 T scanner using high b-value DW-MRS at long diffusion times
Dominik Weidlich, Andreas Hock, Stefan Ruschke, Daniela Franz, Katja Steiger, Thomas Skurk, Hans Hauner, Ernst Rummeny, Dimitrios Karampinos
Despite its strong relevance in metabolism, non-invasive measurement of adipocyte size remains an unmet need. High b-value DW-MRS has been previously applied to probe diffusion restriction effects of intramyocellular lipids or brown adipocytes using preclinical systems with strong gradient systems. The present work proposes a methodology to in vivo probe diffusion restriction effects in bone marrow adipocytes with high b-value long diffusion time DW MRS in a clinical system and examines the feasibility of bone marrow adipocyte size estimation in the tibia of healthy subjects.

Quantifying Fat Mass and Energy Content in Brown Adipose Tissue
Jedrzej Burakiewicz, Gustavo de Abreu Vieira, Laura Janssen, Kimberly Nahon, Mariėtte Boon, Andrew Webb, Hermien Kan, Patrick Rensen
MRI of Brown Adipose Tissue (BAT) is gaining popularity as an alternative to PET-CT. Most commonly used marker in quantifying BAT is fat fraction, however there is no consensus to the range of fat fractions separating BAT and WAT. In this work we show how calculating energy content and total fat mass allows to avoid partial volume effect and provides more quantitative markers than fat fraction. We also argue that the fat fractions in the high end of the range (80% - 100%) contribute significantly to BAT activity. 

Metabolic Imaging of Dynamic Fat Mobilization in Activated Brown Adipose Tissue
Jadegoud Yaligar, Sanjay Kumar Verma , Venkatesh Gopalan , Tian Xianfeng, Anantharaj Rengaraj, S. Sendhil Velan
Brown adipose tissue (BAT) is a target fat compartment for  treatment of metabolic diseases due to its high metabolic capacity. BAT is major site for adaptive thermogenesis involving uncoupling protein-1. We have studied the dynamic oxidative fat metabolism in interscapular brown adipose tissue by activation of β3-adrenergic receptors. Progressive reduction of the lipids from iBAT region is indicative of oxidative metabolism by utilizing the lipids as fuel substrate. Evaluation of lipid mobilization in real time is important to assess the altered metabolic rate and mitochondrial biogenesis involving lipid oxidative metabolism.

Measurement of Brown Adipose Tissue Activity in Response to Thermal Challenges Using Dixon MRI
Jie Deng, Nicholas Rubert, Lisa Neff, Richard Shore, Christina Sammet, Jonathan Samet
Brown adipose tissue (BAT) is the primary site of adaptive thermogenesis, which may play a potential role in the pathogenesis and treatment of obesity, and related metabolic disorders. The purpose of this study is to use Dixon MRI to measure BAT tissue properties under pre-cold, post-cold individualized non-shivering thermogenesis, and re-warm-up conditions, in order to evaluate BAT activity among normal-weight, over-weight and obese subjects.

Realistic 4D abdominal phantom for magnetic resonance imaging
Wei-Ching Lo, Yong Chen, Yun Jiang, Vikas Gulani, Nicole Seiberlich
Validation and evaluation of novel data acquisition and reconstruction strategies are major challenges in abdominal magnetic resonance imaging, and particularly in quantitative imaging. Here, a new 4D numerical abdominal phantom combining anatomical morphology, respiratory motion, tissue properties, and physiological function is introduced to enable comparison of different data collection and reconstruction schemes for abdominal MRI.

Towards Addressing Unmet Needs in MR-only Radiotherapy Treatment Planning: The Feasibility of Estimating Electron Density from Quantitative Water/Fat Imaging
Abraam Soliman, Masoud Hashemi, Alex Karotki, William Song
 MR-only treatment planning requires the knowledge of electron density to account for medium heterogeneities during dose calculation. This work introduces a novel perspective for electron density estimation by utilizing quantitative water/fat imaging. Water/fat phantoms with different percentages were scanned on MR and CT. Water/fat separation was performed while correcting (or minimizing) major sources of signal bias. A linear regression model between CT and corrected MR signals was calculated and used to derive MR-based electron density curve. This approach targets radiotherapy applications that require sensitive soft-tissue heterogeneity correction such as prostate and breast low-dose-rate (LDR) brachytherapy.

A Hyperpolarized 13C MRI Approach for Calculating Glomerular Filtration Rate
Eugene Milshteyn, Cornelius von Morze, Jeremy Gordon, Galen Reed, Robert Bok, Daniel Vigneron
The feasibility of calculating glomerular filtration rate (GFR) using hyperpolarized 13C MRI is demonstrated in this project. HP001 is exhibited as a potential probe for GFR calculation due to its long T1, allowing for high spatiotemporal resolution, and favorable filtration properties. Multiple iterations of common clinical sequences, including EPI and bSSFP, were utilized, and each sequence yielded GFR values close to those found in literature. The results shown here indicate potential for a new noninvasive imaging measurement of GFR. 

Measurement of placental oxygenation in a guinea pig model of intrauterine growth restriction
Kevin Sinclair, Lanette Friesen-Waldner, Trevor Wade, Cheryl Vander Tuin, Barbra de Vrijer, Timothy Regnault , Charles McKenzie
We sought to examine the placental oxygenation status in a guinea pig model of intrauterine growth restriction (IUGR). We measured T2* in placentae of IUGR and control fetuses during a maternal oxygen challenge, where imaging was performed at both 20% and 100% inhaled oxygen. IUGR was defined by an elevated brain to liver volume ratio, indicative of blood flow redistribution secondary to fetal hypoxia. No significant difference in ΔT2* was observed, indicating that the placentae of the IUGR fetuses were not hypoxic. Thus we concluded that placental hypoxia is not necessary to induce fetal hypoxia in the guinea pig.

Two-dimensional susceptibility-weighted MRI at 1.5T: preliminary utility in the assessment of the fetal osseous spine
Xin Chen, Guangbin Wang, Tianyi Qian, Wen Liu, Xinhong Wei, Fei Gao
This study aimed to explore the utility of two-dimensional susceptibility-weighted imaging (2D-SWI) for assessing the fetal osseous spine. Whole-spine MRI was performed on fetuses, which included 2D-SWI and T2-weighted true fast imaging with steady-state precession (T2-TrueFISP) sequences. The image quality of the 2D-SWI was superior to the T2-TrueFISP, allowing for improved diagnostic accuracy in the diagnosis of spinal abnormities. 2D-SWI was valuable in elucidating the structures of the fetal osseous spine allowing for better assessment of spinal deformity, especially in the cervical segment of the spine.

Mapping Abdominal Inflammatory Response Using Manganese-Enhanced MRI (MEMRI)
Kun-Han Lu, Jiayue Cao, Lauren Marussich, Tom Hu, Zhongming Liu
We used in vivo Manganese-Enhanced MRI (MEMRI) to image and assess the increase in calcium influx into immune cells so as to report the cellular responses to systemically LPS-induced inflammation throughout the abdomen. We found that: (1) The contrast enhancement was dose- and time-dependent with variation across organs. (2) An increase in Mn2+ uptake was observed in the liver and the kidney, but not in the spleen or the muscle given inflammation. (3) The inflammation-induced enhancement was dependent on the time after the initial exposure to LPS.

The International Society for Magnetic Resonance in Medicine is accredited by the Accreditation Council for
Continuing Medical Education to provide continuing medical education for physicians.