Muscle ultrasonography and computed tomography in elderly trained and untrained women.

Ultrasonography (US) and computed tomography (CT) were compared in studying the associations between long-term physical training and quadriceps muscle mass and structure in female athletes and controls, aged 66-85 years. Muscle cross-sectional area (CSA) measured using US correlated highly with that measured using CT, but the latter technique yielded 30% higher values on average. The echo intensity of the fasciae and bone measured by US correlated positively with the mean radiological density and negatively with the relative proportion of fat obtained from CT. Low intramuscular echo intensity was accompanied by high muscle density and low relative proportion of fat. The athletes had larger quadriceps CSA and more discerned fasciae and connective tissue septa but less fat than the controls. The results indicate that US and CT both are useful methods in comparing muscle mass and structure in elderly trained and untrained women.