Fig. 2.

The grey matter (GM) and white matter (WM) region of interest (ROI) depicted in the schematic drawing of the cross-section of the spinal cord (a, GM and WM ROIs were highlighted in blue and red, respectively). The WM ROI covers parts of the left (L) and right (R) lateral funiculus as well as dorsal (D) and anterior (V) columns. The GM ROI covers parts of the butterfly-shaped GM structure. One example slice (slice position is shown in Fig. 1) of the individual WM and GM ROIs is overlaid on the corresponding FA maps for each subject ((b): subject 1–9). The ROIs were manually defined based on the corresponding reference FA image, which was obtained after slice-wise eddy current and motion correction with robust tensor fitting (method (vi), see Table 2).