Quantification of immobilization-induced changes in human calf muscle using speed-of-sound ultrasound

Short-term immobilization leads to fatty muscular degeneration, which is associated with various negative health effects. Based on literature showing very high correlations between MRI Dixon fat fraction and Speed-of-Sound (SoS), we hypothesized that can detect short-term-immobilization-induced differences in SoS. Both calves of 10 patients a calf cast one side for mean duration 41 ± 26 days were examined relaxed position using standard ultrasound machine. Calf perimeters measured both sides. A flat Plexiglas-reflector, placed vertically the opposite probe in-between, was used as timing reference SoS manually annotated by two readers assessed an automatic annotation algorithm. The thickness values subcutaneous muscle layers read from B-mode images. Differences non-cast calculated paired t test. Correlation analysis perimeter performed Pearson's correlation coefficient. Paired test showed significant (P < .01) leg .001). reduced number after installment (r = −0.553, P .097). No found layer thickness, echo intensity, or intensity. Short-term-immobilization led reduction compared healthy calf, indicating potential role biomarker detecting immobilization-induced degeneration not visible ultrasound.