title: Muscle-fat MRI: 1.5 Tesla and 3.0 Tesla versus histology.
abstract: BACKGROUND
  We evaluated muscle/fat fraction (MFF) accuracy and reliability measured with an MR imaging technique at 1.5 Tesla (T) and 3.0T scanner strengths, using biopsy as reference.
  
  
  METHODS
  MRI was performed on muscle samples from pig and rabbit species (n = 8) at 1.5T and 3.0T. A chemical shift based 2-point Dixon method was used, collecting in-phase and out-of-phase data for fat/water of muscle samples. Values were compared with MFFs calculated from histology.
  
  
  RESULTS
  No significant difference was found between 1.5T and 3.0T (P values = 0.41-0.96), or between histology and imaging (P = 0.83) for any muscle tested.
  
  
  CONCLUSIONS
  RESULTS suggest that a 2-point Dixon fat/water separation MRI technique may provide reliable quantification of MFFs at varying field strengths across different animal species, and consistency was established with biopsy. The results set a foundation for larger scale investigation of quantifying muscle fat in neuromuscular disorders.
authors.affiliation: Northwestern University Interdepartmental Neuroscience Program, Chicago, Illinois, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Smith
authors.forename: Todd B
authors.initials: TB
authors.lastname: Parrish
authors.forename: Rebecca
authors.initials: R
authors.lastname: Abbott
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hoggarth
authors.forename: Karl
authors.initials: K
authors.lastname: Mendoza
authors.forename: Yu Fen
authors.initials: YF
authors.lastname: Chen
authors.forename: James M
authors.initials: JM
authors.lastname: Elliott
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000818:Animals; D001706:Biopsy; D008279:Magnetic Resonance Imaging; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D011817:Rabbits; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013552:Swine
keywords: MRI; fat; muscle; muscle fat infiltrates; muscle imaging; muscle/fat fraction