title: MRI allows for longitudinal quantitative analysis of body fat composition in rats: an analysis of sibutramine-associated changes at the group level.
abstract: OBJECTIVE
  Body fat distribution changes are associated with multiple alterations in metabolism. Therefore, the assessment of body fat compartments by MRI in animal models is a promising approach to obesity research. Standard T1-weighted (T1w) whole body MRI was used here to quantify different effects in the subcutaneous and visceral fat compartments in rats under treatment with an anorexiant.
  
  
  METHODS
  Twenty rats on a high caloric diet were investigated by the identical MRI protocol at baseline and after seven weeks. Ten rats received a treatment with sibutramine, 10 rats served as vehicle control group. To longitudinally assess body fat components, MRI analysis was used with two approaches: 2D slicewise graphic analysis (SGA) was compared with an automated 3D analysis algorithm (3DA).
  
  
  RESULTS
  At the group level, fat volume differences showed a longitudinal increase of subcutaneous and visceral fat volumes for the control group, whereas the sibutramine group showed stable subcutaneous fat volumes and decrease in visceral fat volumes. SGA and 3DA volume determination showed significant correlations for subcutaneous fat volume (C=0.85, p<0.001), visceral fat volume (C=0.87, p<0.001), and total fat volume (C=0.90, p<0.001).
  
  
  CONCLUSIONS
  It could be demonstrated that computer-based analysis of T1w MRI could be used to longitudinally assess changes in body fat compartments in rats at the group level. In detail, it was possible to investigate the effect of sibutramine separate on the fat compartments in rats.
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Müller
authors.forename: Heiko G
authors.initials: HG
authors.lastname: Niessen
authors.forename: Thomas
authors.initials: T
authors.lastname: Kaulisch
authors.forename: Albert C
authors.initials: AC
authors.lastname: Ludolph
authors.forename: Jan
authors.initials: J
authors.lastname: Kassubek
authors.forename: Detlef
authors.initials: D
authors.lastname: Stiller
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000465:Algorithms; D000818:Animals; D001067:Appetite Depressants / Q000737:chemistry*; D001823:Body Composition; D050218:Body Fat Distribution / Q000379:methods*; D003196:Computer Graphics; D003503:Cyclobutanes / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D050152:Intra-Abdominal Fat / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009765:Obesity / Q000473:pathology; D051381:Rats; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio
chemical_list: D001067:Appetite Depressants; D003503:Cyclobutanes; C058254:sibutramine
keywords: Body fat composition; Magnetic resonance imaging; Rats; Sibutramine; Subcutaneous fat volume; Visceral fat volume