Additional file 1: Supplementary Figure 1. Definition of the oval ROIs in the three axial slices for quantitative T2 analysis. A Based on the first TE image from the MSME MRI scan, the three slices immediately below the knee bones were selected for ROI placements as shown by the yellow ovals. B T2 maps with the yellow oval ROIs show that these ROIs avoid fibula, larger blood vessels, and the subcutaneous fat. Each ROI is 160 pixels (6.1 mm2) and covers the posterior part of the hindlimb which mainly include gastrocnemius, soleus, and plantaris muscles. ROI: regions of interest, T2: transverse relaxation time constant, TE: echo time, MSME: multi-slice multi-echo, MRI: magnetic resonance imaging.