Fig. 4
a The traced outlines of anterior compartments of the affected and normal limbs in the axial plane, which were used to measure anterior compartment cross-sectional areas (CSAs). The cross-sectional area ratio (CSAR) of the affected limb to the normal limb was calculated to evaluate the recovery of skeletal muscle volume. b T2-weighted image obtained in the coronal plane. Two regions of interest (ROIs), each with an area of 1 cm2, were chosen at identical locations in the affected and normal limbs . Vascular and fascial structures were kept outside the ROIs. The average T2-weighted signal intensity (T2SI) of the ROI was calculated for the affected limb and for the normal limb; the ratio of these T2SIs—the average T2-weighted signal intensity ratio (T2SIR)—was used to assess the recovery of skeletal muscle internal structures. Note the high-signal lesion in the medullary cavity of the affected tibia after the removal of the intramedullary nail