Related Experiment Video
Updated: Jun 24, 2026
Segmentation and Measurement of Fat Volumes in Murine Obesity Models Using X-ray Computed Tomography
Published on: April 4, 2012
Evaluating Sex-specific Differences in Abdominal Fat Volume and Proton Density Fat Fraction at MRI Using Automated
Arun Somasundaram1, Mingming Wu1, Anna Reik1
1From the Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar (A.S., M. Wu, S.R., J.H., S.N., D.J., L.P., D.C.K.), Institute of Nutritional Medicine, School of Medicine (A.R., M. Wiechert, H.H., C.H.), TUM School of Computation, Information, and Technology (Y.Z., D.R.), TUM School of Medicine and Health (D.R.), and Else Kröner Fresenius Center for Nutritional Medicine, School of Medicine (H.H.), Technical University of Munich, Ismaninger Str 22, 81675 Munich, Germany; Department of Computing, Imperial College London, London, UK (D.R.); Department of Nutritional, Food and Consumer Sciences, Fulda University of Applied Sciences, Fulda, Germany (C.H.); and Munich Institute of Biomedical Engineering and Munich Data Science Institute, Technical University of Munich, Garching, Germany (D.C.K.).
Abstract:
Sex-specific abdominal organ volume and proton density fat fraction (PDFF) in people with obesity during a weight loss intervention was assessed with automated multiorgan segmentation of quantitative water-fat MRI. An nnU-Net architecture was employed for automatic segmentation of abdominal organs, including visceral and subcutaneous adipose tissue, liver, and psoas and erector spinae muscle, based on quantitative chemical shift-encoded MRI and using ground truth labels generated from participants of the Lifestyle Intervention (LION) study. Each organ's volume and fat content were examined in 127 participants (73 female and 54 male participants; body mass index, 30-39.9 kg/m2) and in 81 (54 female and 32 male participants) of these participants after an 8-week formula-based low-calorie diet. Dice scores ranging from 0.91 to 0.97 were achieved for the automatic segmentation. PDFF was found to be lower in visceral adipose tissue compared with subcutaneous adipose tissue in both male and female participants. Before intervention, female participants exhibited higher PDFF in subcutaneous adipose tissue (90.6% vs 89.7%; P < .001) and lower PDFF in liver (8.6% vs 13.3%; P < .001) and visceral adipose tissue (76.4% vs 81.3%; P < .001) compared with male participants. This relation persisted after intervention. As a response to caloric restriction, male participants lost significantly more visceral adipose tissue volume (1.76 L vs 0.91 L; P < .001) and showed a higher decrease in subcutaneous adipose tissue PDFF (2.7% vs 1.5%; P < .001) than female participants. Automated body composition analysis on quantitative water-fat MRI data provides new insights for understanding sex-specific metabolic response to caloric restriction and weight loss in people with obesity. Keywords: Obesity, Chemical Shift-encoded MRI, Abdominal Fat Volume, Proton Density Fat Fraction, nnU-Net ClinicalTrials.gov registration no. NCT04023942 Supplemental material is available for this article. Published under a CC BY 4.0 license.
