Qin-He Zhang¹, Li-Zhi Xie², and Ai-Lian Liu^1
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²MR Research, Beijing, China

This study assessed the correlation between hepatic and pancreatic steatosis and cardiometabolic risk factors. The results showed that hepatic and pancreatic FF were associated with specific risk factors, and the correlation coefficient varied by sex. This plays an important role in our further understanding about the association between ectopic fat deposition and cardiometabolic risk factors. Hepatic and pancreatic steatosis might have important implication for prevention cardiometabolic risk factors.

Soham A Shah¹, Brent French¹, Matthew Wolf¹, and Fred Epstein^1
1University of Virginia, Charlottesville, VA, United States

Epicardial adipose tissue (EAT) volume and fatty acid composition (FAC) have significant roles in EAT-mediated coronary vascular inflammation. Using MRI of EAT volume and FAC, we tested the hypothesis that eplerenone reduces EAT volume and alters its FAC in a mouse model of obesity. We show that eplerenone significantly reduces EAT volume after 30 weeks on a high-fat high-sucrose diet compared to untreated mice. In addition, the EAT FAC is shifted from saturated fatty acid dominant in untreated mice to poly-unsaturated fatty acid dominant in eplerenone-treated mice. The results suggest that eplerenone has an anti-inflammatory role in obesity-related EAT.

Ishu Arpan¹, William D Rooney¹, Rebecca J Willcocks², Alison M Barnard², Sean C Forbes², William T Triplett², Eric Baetscher¹, Michael J Daniels², Glenn A Walter², and Krista Vandenborne^2
1Oregon Health & Science University, Portland, OR, United States, ²University of Florida, Gainesville, FL, United States

Duchenne muscular dystrophy (DMD) is a genetic disease characterized by rapidly progressing weakness and degeneration of the skeletal muscles. This study presents a modeling approach using MR biomarkers  to characterize disease progression in individuals with DMD receiving deflazacort, prednisone/prednisolone, or no corticosteroid treatment. The findings from a sample of convenience compiled from the ImagingDMD study demonstrate that 1) corticosteroid treatment slows DMD disease progression, with deflazacort slowing progression to a greater extent than prednisone/prednisolone, and 2) the slow-progressing muscles in DMD are more sensitive to treatment effects, and hence, could be better candidates to assess therapeutic response in clinical trials. 

Dragana Savic¹, Ferenc E. Mózes¹, Matthew K. Burrage¹, Leanne Hodson¹, Stefan Neubauer¹, Michael Pavlides¹, Damian J. Tyler¹, and Ladislav Valkovic^1
1University of Oxford, Oxford, United Kingdom

This study investigated the in vivo effects on acetylcarnitine levels in the heart and the liver after an injection of L-carnitine. Carnitine acts as a buffer of acetyl-CoA units in the mitochondria, as well as facilitating transport of fatty acids. We show that an injection of L-carnitine can alter cardiac lipid levels in the in vivo healthy human. However, even though L-carnitine injection shows high cardiac variability in acetylcarnitine levels, hepatic variability of acetylcarnitine levels were reduced. Further studies are needed to confirm the dose and time-frame of a response in acetylcarnitine levels after L-carnitine injections.

Jonathan Philip Lam¹, Leila Neshatian², Brooke Gurland³, and Vipul Sheth^4
1Radiology, Stanford University, Palo Alto, CA, United States, ²Gastroenterology, Stanford University, Palo Alto, CA, United States, ³General Surgery, Stanford University, Palo Alto, CA, United States, ⁴Stanford University, Palo Alto, CA, United States

Pelvic floor disorders (PFDs) are a very common group of clinical conditions that affect nearly 50% of women aged 80 years or older. While pelvic floor disorders are thought to be associated with pelvic floor muscle weakness, there has not been an established correlation between sarcopenia and PFDs. This single institution, retrospective study evaluates the effect of decreased muscle quantity/quality on severity of pelvic organ prolapse. Our findings suggest increased psoas and puborectalis muscle fat fraction are associated with higher grades of pelvic organ prolapse.

Robin A. Damion^1,2,3, Daniel J. Cocking^3,4, Brett Haywood^3,4, Matthew S. Brook^2,5,6, Paul L. Greenhaff^2,5,6, Philip J. Atherton^1,2,5, Dorothee P. Auer^1,2,3, and Richard Bowtell^2,3,4
1School of Medicine, University of Nottingham, Nottingham, United Kingdom, ²NIHR Nottingham Biomedical Research Centre/Nottingham Clinical Research Facilities, University of Nottingham, Nottingham, United Kingdom, ³Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, ⁴School of Physics & Astronomy, University of Nottingham, Nottingham, United Kingdom, ⁵MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, United Kingdom, ⁶School of Life Sciences, University of Nottingham, Nottingham, United Kingdom

Deuterium spectra of the human calf were obtained at natural abundance, at 3 T field strength. Two peaks with a chemical shift separation of 3.5 ppm were observed, corresponding to water and lipids, and their relaxation times T₁ and T₂* were measured using a transceive surface coil. Utilising the complex data to fit spectral lines, including independent phases for each peak, and fitting the complex inversion-recovery data enabled measurements of T₁ which could be frustrated by inversion-time-dependent phases caused by RF imperfections. The results indicate that such measurements in humans are possible despite the low natural abundance of ²H.  

Stefan Ruschke¹, Julius Honecker², Dominik Weidlich¹, Claudine Seeliger², Olga Prokopchuk³, Josef Ecker⁴, Marcus R. Makowski¹, Hans Hauner², and Dimitrios C. Karampinos^1
1Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany, ²Else Kröner Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany, ³Department of Surgery, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Munich, Germany, ⁴ZIEL Institute for Food & Health; Research Group Lipid Metabolism, Technical University of Munich, Freising, Germany

Short-TR multi-TI multi-TE (SHORTIE) STEAM is a promising technique for the characterization of adipose tissue since it allows the non-invasive simultaneous probing of triglyceride fatty acid composition and triglyceride T1- and T2-relaxation times. The present in vitro study of human adipose tissue aims at the validation of the SHORTIE-assessed triglyceride fatty acid composition with gas chromatography–mass spectrometry and investigates potential correlations of the triglyceride relaxation properties with adipocyte cell size from histology.

Zimeng Cai^1,2, Quan Tao^1,2, Alessandro Scotti^3,4, Peiwei Yi^1,2, Yanqiu Feng^1,2, and Kejia Cai^3,4
1School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China, ²Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong, China, ³The Department of Radiology and Bioengineering, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States, ⁴Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States

To investigate the capability of Z-spectral magnetic resonance imaging (ZS-MRI) for the quantification of marrow adipose tissue (MAT) content in rat’s lumbar spine and to monitor the MAT changes due to age. First, three sets of water-oil mixed phantoms prepared with varying fat fractions (FF) were scanned and the quantification results were compared to ¹H-MRS and Dixon’s MRI methods. Then, ZS-MRI was used to longitudinally monitor the adiposity in the lumbar spine of healthy-young rats at 13, 17 and 21 weeks along with ¹H-MRS and Dixon’s MRI. The changes over time in FF of MAT were confirmed by histology staining.

Silvia Capuani^1,2, Roberto Coccurello³, Riccardo De Feo⁴, Lorenzo Rossi⁵, Giulia Tuttobene⁵, Emanuele Agrimi⁵, Clelia Raso⁵, Federico Giove^2,4, and Umberto Tarantino^6
1Physics Dpt Sapienza, CNR ISC, Rome, Italy, ²Santa Lucia foundation, Rome, Italy, ³CNR ISC, Rome, Italy, ⁴Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome, Italy, ⁵Physics Dpt., Sapienza University, Rome, Italy, ⁶Tor Vergata University, PTV, Rome, Italy

Aim of this study was to identify relevant changes in the metabolic profile of bone-marrow and muscle during healthy aging in both men and women. Towards this goal, single-voxel MRS with STEAM at TE=6ms and T2 evaluation of each resonance was performed. Bone-marrow fatty-acids quantification show a clear sex dimorphism with normal aging while no significant differences were found in the muscle metabolites of female and male subjects. On the other hand, metabolite-T2 values were different in male and female resonances and significant T2 differences among 36+, 36-52 and 52+ group, finding higher T2 in older group were observed.

Qin-He Zhang¹, Li-Zhi Xie², and Ai-Lian Liu^1
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²MR Research, Beijing, China

This study assessed the correlation between preperitoneal fat and hepatic and pancreatic steatosis. The results showed that hepatic FF and pancreatic FF were strongly associated with preperitoneal fat fraction and area. This plays an important role in our further understanding of fat distribution and ectopic fat deposition.

Orlando Aristizabal¹, Lakshmi Arivazhagan¹, AnnMarie Schmidt¹, Edward A Fisher ¹, Kathryn Moore¹, and Youssef Zaim Wadghiri^1
1NYU Grossman School of Medicine, New York, NY, United States

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the Western The development of preclinical mouse models is essential in the development of virtual biopsy protocols to assess the essential features of NAFLD.    In this report we have examined the feasibility of visualizing and mapping the fat fraction in mice under 2 high fat diets and one control diet using a preclinical 3-Tesla MRI with a RARE-Dixon sequence.  We show that at 3T fat and water can be separated and percentage maps show a 23% and 39% increase in liver fat over the control mouse.

Gang Liu¹, Rongrong Zhu², Ruoshui Ha², and Xiuzheng Yue^3
1People’s Hospital of Fuyang, Fuyang, China, ²People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan, China, ³Philips Healthcare, Beijing, China

To prospectively study the changes of adipose content, adipose tissue edema and fibrosis in the orbit of Thyroid-associated ophthalmopathy (TAO) by mDixon-Quant imaging and investigate their application to TAO activity assessment. The result showed T2* values may be a promising marker for assessing the activity of TAO.

Sheng-Qing Lin¹, Sebastian Fonseca¹, Durga Udayakumar¹, Neela Batthula¹, Ivan E. Dimitrov^2,3, Ivan Pedrosa¹, and Ananth J. Madhuranthakam^1
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, ²Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, ³Philips, Dallas, TX, United States

Mapping fat fraction (FF) has been proposed as a biomarker of treatment response in multiple myeloma. Whole-body imaging using 2-point Dixon methods offer efficient acquisitions but may suffer from less accurate FF quantification than multi-echo Dixon. Using our previously developed whole-body MR sequence with 2-point turbo spin-echo (TSE) Dixon, we generated accurate FF maps using with a fat masking algorithm. Results from a fat-water phantom and in vivo images show that 2-point TSE-Dixon with the fat masking algorithm performed comparably to multi-echo Dixon, facilitating accurate FF maps in whole-body MRI.

Christian Guenthner¹, Hannes Dillinger¹, Peter Boernert^2,3, and Sebastian Kozerke^1
1University and ETH Zurich, Zurich, Switzerland, ²Philips Research, Hamburg, Germany, ³Leiden University Medical Center, Leiden, Netherlands

Water/fat separation can be performed by exploiting chemical shift, which is proportional to field strength. Hence, on lower-field MRI systems (0.1 … 1T), the absolute resonance frequency difference is reduced compared to clinical high-field MRI, raising the question if water/fat separation can still be reliably performed despite the proximity of the resonances. In this work, we examined the feasibility of Dixon-type water/fat separation in the abdomen on a 0.75T lower-field MRI system. We show that Cartesian multi-acquisition and multi-echo as well as spiral multi-acquisition sequences provide reliable water/fat separation despite the reduced water/fat resonance shift of approximately 108 Hz.

Xiaodong Zhong¹, Tess Armstrong^2,3, Chang Gao^2,3, Marcel Dominik Nickel⁴, Fei Han¹, Brian Dale⁵, Holden Wu^2,3, Peng Hu^2,3, and Vibhas Deshpande^6
1MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Los Angeles, CA, United States, ²Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, ³Physics and Biology in Medicine Interdepartmental Program, University of California Los Angeles, Los Angeles, CA, United States, ⁴MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, ⁵MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Cary, NC, United States, ⁶MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Austin, TX, United States

For liver proton density fat fraction (PDFF) and R₂^* quantification, free-breathing three-dimensional stack-of-radial MRI may perform a calibration scan for k-space shift correction. This study proposes an accelerated k-space shift calibration method. The proposed method was validated in a PDFF/R₂^* phantom with vendor-provided ground truth. Preliminary in vivo results demonstrated good agreement in the liver PDFF/R₂^* compared to the reference breath-hold Cartesian MRI. This proposed method enabled a 3-fold reduction in calibration time (20 seconds or more) for the in vivo protocols in this study. It may allow more efficient free-breathing PDFF/R₂^* mapping in patient populations with breath-hold difficulties.

Elizabeth Huaroc¹, Dominik Weidlich¹, Thomas Amthor², Peter Koken², Manuel Baumann², Kilian Weiss³, Marcus Makowski¹, Benedikt Schwaiger⁴, Mariya Doneva², and Dimitrios Karampinos^1
1Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany, ²Philips Research Lab, Hamburg, Germany, ³Philips Healthcare, Hamburg, Germany, ⁴Department of Diagnostic and Interventional Neuroradiology, Technical University of Munich, Munich, Germany

Dixon Magnetic Resonance Fingerprinting (Dixon-MRF) has been emerging for achieving efficient fat suppression in body applications of MRF. Fat quantification using traditional Dixon imaging relies on a pre-calibrated proton density fat spectrum. The fat spectrum is known to be composed of different fat peaks, which have different relaxation times and are affected by J-coupling modulations. Existing Dixon-MRF methods perform water-fat separation assuming a constant pre-calibrated fat spectrum and not accounting how the complex fat spectrum varies along the MRF flip angle train. The present work proposes a framework to characterize the effect of fat spectrum complexity in Dixon-MRF.

Shu-Fu Shih^1,2, Sevgi Gokce Kafali^1,2, Tess Armstrong¹, Xiaodong Zhong³, Kara L. Calkins⁴, and Holden H. Wu^1,2
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, ²Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, ³Siemens Medical Solutions USA, Inc., Los Angeles, CA, United States, ⁴Pediatrics, University of California, Los Angeles, Los Angeles, CA, United States

Self-gated free-breathing multi-echo stack-of-radial MRI quantifies liver fat and R₂*. However, data undersampling due to motion self-gating can degrade the image quality and quantification accuracy. Previous methods required either longer scan time or computationally expensive constrained reconstruction. In this work, a deep learning-based two-stage network was developed to suppress undersampling artifacts and rapidly generate quantitative fat and R₂* maps with a pixel-wise uncertainty map. The proposed method achieved accurate fat and R₂* mapping and reduced the computational time by two orders of magnitude versus constrained reconstruction. The uncertainty map can be used to detect regions with potential quantification errors.

Jonathan K. Stelter¹, Christof Boehm¹, Stefan Ruschke¹, Maximilian N. Diefenbach^1,2, Mingming Wu¹, Kilian Weiss³, Tabea Borde¹, Stephan Metz¹, Marcus R. Makowski¹, and Dimitrios C. Karampinos^1
1Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany, ²Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich, Munich, Germany, ³Philips Healthcare, Hamburg, Germany

Patients with silicone breast implants undergoing MR mammography are examined with a water- and fat-suppressed sequence to verify the implant’s integrity. In parallel, chemical shift encoding-based water–fat separation has been recently used for quantifying breast water-fat composition to assess breast density and for extracting magnetic susceptibility maps to detect breast calcifications. In this work, a water–fat–silicone separation method is developed for a joint estimation of all three components and applied with NSA-optimized echo times to simulated single-voxel data, scanner phantom and in vivo data showing robust species separation and fat fraction mapping.

Utsav Shrestha¹, Marie Van Der Merwe², Nirman Kumar³, Eddie Jacobs⁴, Sanjaya Satapathy⁵, Cara Morin⁶, and Aaryani Tipirneni-Sajja^1,6
1Biomedical Engineering, The University of Memphis, Memphis, TN, United States, ²College of Health Sciences, The University of Memphis, Memphis, TN, United States, ³Computer Science, The University of Memphis, Memphis, TN, United States, ⁴Electrical & Computer Engineering, The University of Memphis, Memphis, TN, United States, ⁵North Shore University Hospital/Northwell Health, Manhasset, NY, United States, ⁶St. Jude Children’s Research Hospital, Memphis, TN, United States

Multi-spectral fat-water models assume either single or independent R2* for water (R2*W) and fat (R2*F) for assessment of steatosis. However, any incorrect assumptions in the signal model will produce errors in R2* and fat fraction (FF) calculations. In this study, we developed a Monte Carlo–based approach for generating steatosis models by characterizing fat morphology from histology and synthesizing MRI signal to estimate independent R2*W and R2*F and compare with in-vivo studies. Our results show that R2*W and R2*F are slightly different at low FFs and both demonstrate a positive correlation with FF with slopes of R2*W-FF similar to in-vivo calibrations.

Pohchoo Seow¹, K Rashid², Vairavan Narayanan ³, Azlina Ahmad-Annuar ⁴, Jeannie Wong², Li Kuo Tan², K Ibrahim⁴, and Norlisah Ramli^2
1Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore, ²Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia, ³Department of Surgery, University of Malaya, Kuala Lumpur, Malaysia, ⁴Department of Biomedical Science, University of Malaya, Kuala Lumpur, Malaysia

We explored the relationships between MRI lipid-imaging signatures and sterol regulatory element binding proteins (SREBPs) gene expression profiling of ten histologically proven glioma patients to elucidate the underlying inter- & intra-tumoural lipid distribution changes. The high expression of SREBPs was observed for grade II and III implied reprogramming of lipid metabolism. The identification of imaging biomarkers that can reflect changes in the genetic profiles of SREBP offers a new avenue for personalised medicine and the development of new therapeutic targets.