title: Reproducibility of single- and multi-voxel 1H MRS measurements of intramyocellular lipid in overweight and lean subjects under conditions of controlled dietary calorie and fat intake.
abstract: The reproducibility of repeated single-voxel 1H MRS (SV-MRS) and spectroscopic imaging (MRSI) measurements of intramyocellular lipid (IMCL) in the tibialis anterior muscle of five lean and five overweight female Caucasians, during 7 days of controlled dietary fat and calorie intake, was assessed at 1.5 T. Duplicate measures of IMCL relative to total muscle creatine (IMCL/tCr) obtained 3 days apart by both SV-MRS and MRSI correlated well (r = 0.65 and r = 0.95, respectively, P < 0.05). The coefficients of variation for repeated measures of IMCL/tCr by SV-MRS and MRSI were 24.4% and 10.7%, respectively. IMCL/tCr measured by MRSI was higher in overweight subjects than in lean subjects (8.3 +/- 3.8 vs 4.3 +/- 2.4, P < 0.05). Although both methods achieved good reproducibility in measuring IMCL in vivo, MRSI was found to offer greater flexibility and reliability, and higher sensitivity to IMCL differences, whereas SV-MRS was advantageous with respect to shorter scan time and ease of implementation.
authors.affiliation: Obesity Research Center, St Luke's-Roosevelt Hospital and Institute of Human Nutrition, Columbia University, New York, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Xiangling
authors.initials: X
authors.lastname: Mao
authors.forename: Carla
authors.initials: C
authors.lastname: Wolper
authors.forename: Stanley
authors.initials: S
authors.lastname: Heshka
authors.forename: Stephen
authors.initials: S
authors.lastname: Dashnaw
authors.forename: Joy
authors.initials: J
authors.lastname: Hirsch
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Dikoma C
authors.initials: DC
authors.lastname: Shungu
mesh_terms: D000328:Adult; D035843:Biomedical Research / Q000379:methods; D031204:Caloric Restriction; D003404:Creatinine / Q000032:analysis; D018752:Diet, Fat-Restricted; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000032:analysis / Q000528:radiation effects; D007866:Leg / Q000503:physiopathology; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D050177:Overweight / Q000503:physiopathology*; D012016:Reference Values; D015203:Reproducibility of Results; D012107:Research Design
chemical_list: D008055:Lipids; D006859:Hydrogen; D003404:Creatinine