1. LEM mass, volume, and signal intensity
DXA (Lunar iDXA for Bone Health; GE Healthcare, Schenectady, NY, USA) was used to analyze the LEM mass. A lateral whole-body scan was performed according to the enCORE-based X-ray Bone Densitometer User Manual. After the lateral DXA scan was performed, the region of interest was defined to analyze the LEM composition [L-S spine 3D-MRI was performed at baseline (week 0) and after the intervention (week 12) using a 1.5-T scanner (Achieva 1.5 T; Philips Healthcare, Netherlands). The imaging protocol included sagittal T2-weighted fast spin-echo imaging and axial T2-weighted fast spin-echo imaging. Axial images (five slices) were obtained for each lumbar intervertebral level (T12/L1 to L4/5) parallel to the vertebral endplates. Three-dimensional segmentation of the LEM was performed to measure the mean volume and signal intensity. The right and left LEM compartments were segmented separately from the mid-disc level of T12/L1 to the mid-disc level of L4/5. A semi-automated random walk 3D segmentation algorithm, a magic cut tool for segmentation within radiological software (MEDIP; MEDICALIP, Seoul, South Korea), was used to volumetrically segment the LEM (Fig. 