Reliability of in vivo determination of forearm muscle volume using 3.0 T magnetic resonance imaging.
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%.
Smeulders
M J C
MJ
Department of Plastic, Reconstructive and Hand Surgery, Academic Medical Center Amsterdam, University of Amsterdam, the Netherlands. m.j.smeulders@amc.nl
van den Berg
S
S
Oudeman
J
J
Nederveen
A J
AJ
Kreulen
M
M
Maas
M
M
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