title: Cadaver validation of skeletal muscle measurement by magnetic resonance imaging and computerized tomography.
abstract: Magnetic resonance imaging (MRI) and computerized tomography (CT) are promising reference methods for quantifying whole body and regional skeletal muscle mass. Earlier MRI and CT validation studies used data-acquisition techniques and data-analysis procedures now outdated, evaluated anatomic rather than adipose tissue-free skeletal muscle (ATFSM), studied only the relatively large thigh, or found unduly large estimation errors. The aim of the present study was to compare arm and leg ATFSM cross-sectional area estimates (cm2) by using standard MRI and CT acquisition and image-analysis methods with corresponding cadaver estimates. A second objective was to validate MRI and CT measurements of adipose tissue embedded within muscle (interstitial adipose tissue) and surrounding muscle (subcutaneous adipose tissue). ATFSM area (n = 119) by MRI [38.9 +/- 22.3 (SD) cm2], CT (39.7 +/- 22.8 cm2), and cadaver (39.5 +/- 23.0 cm2) were not different (P > 0.001), and both MRI and CT estimates of ATFSM were highly correlated with corresponding cadaver values [MRI: r = 0.99, SE of estimate (SEE) 3.9 cm2, P < 0.001; and CT: r = 0.99, SEE = 3.8 cm2, P < 0.001]. Similarly good results were observed between MRI- and CT-measured vs. cadaver-measured interstitial and subcutaneous adipose tissue. For MRI-ATFSM the intraobserver correlation for duplicate measurements in vivo was 0. 99 [SEE = 8.7 cm2 (2.9%), P < 0.001]. These findings strongly support the use of MRI and CT as reference methods for appendicular skeletal muscle, interstitial and subcutaneous adipose tissue measurement in vivo.
authors.affiliation: School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: N
authors.initials: N
authors.lastname: Mitsiopoulos
authors.forename: R N
authors.initials: RN
authors.lastname: Baumgartner
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: W
authors.initials: W
authors.lastname: Lyons
authors.forename: D
authors.initials: D
authors.lastname: Gallagher
authors.forename: R
authors.initials: R
authors.lastname: Ross
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology; D002102:Cadaver; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007866:Leg / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D009765:Obesity / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed