title: Reliability of in vivo determination of forearm muscle volume using 3.0 T magnetic resonance imaging.
abstract: OBJECTIVE
  To apply magnetic resonance imaging (MRI) as a tool for quantifying muscle volume of forearm muscles feasibility and reliability of volume estimation of the flexor carpi ulnaris (FCU) and the extensor carpi ulnaris (ECU).
  
  
  METHODS
  Forearms of 10 subjects were scanned twice. Muscle volumes were calculated from manual outlines on axial slices, slice thickness, and the number of slices. Observer agreement and repeatability were estimated using intraclass correlation, coefficient of variation, and the smallest detectable difference.
  
  
  RESULTS
  The average volume of the FCU and ECU was 31.0 mL (SD 11.5 mL) and 16.4 mL (SD 7.7 mL), respectively. Intraclass correlation coefficients of the volumes were all above 0.99 and the coefficient of variation varied between 5.7% and 0.8%. The smallest detectable difference corresponded to approximately 7% of muscle volume.
  
  
  CONCLUSIONS
  MRI muscle volume measurement of forearm muscles is feasible, reproducible, and allows for longitudinal studies where expected responsiveness exceeds 7%.
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, Academic Medical Center Amsterdam, University of Amsterdam, the Netherlands. m.j.smeulders@amc.nl
authors.forename: M J C
authors.initials: MJ
authors.lastname: Smeulders
authors.forename: S
authors.initials: S
authors.lastname: van den Berg
authors.forename: J
authors.initials: J
authors.lastname: Oudeman
authors.forename: A J
authors.initials: AJ
authors.lastname: Nederveen
authors.forename: M
authors.initials: M
authors.lastname: Kreulen
authors.forename: M
authors.initials: M
authors.lastname: Maas
mesh_terms: D000328:Adult; D005260:Female; D005542:Forearm / Q000033:anatomy & histology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult