title: Relationship between MRI relaxation time and muscle fiber composition.
abstract: The relationship between nuclear magnetic resonance relaxation time obtained with magnetic resonance imaging (MRI) and muscle fiber composition of the lateral gastrocnemius was examined in 13 men. There was a positive correlation (r = 0.80, P < or = 0.001) between longitudinal relaxation time and the relative percentage of slow-twitch muscle fibers (type I). There was no relationship between transverse relaxation time and type I percentage (r = 0.17, P = 0.57). These results suggest that MRI longitudinal relaxation time can be used for the noninvasive estimation of muscle fiber composition in humans.
authors.affiliation: Human Performance Laboratory, East Carolina University, Greenville, North Carolina 27858, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Houmard
authors.forename: R
authors.initials: R
authors.lastname: Smith
authors.forename: G L
authors.initials: GL
authors.lastname: Jendrasiak
mesh_terms: D000328:Adult; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000145:classification / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D012044:Regression Analysis