Fig. 1.

Examples of the definition of the regions of interest for quantitative analysis. MTR_asym(3.5 ppm), ${\mathrm{MTR}}_{\mathrm{asym}}^{\mathrm{total}}$ and MTR(15.6 ppm) were measured for each region. The values of each side were recorded as separate samples. The median voxel numbers of the substantia nigra (blue), red nucleus (pink), globus pallidus (yellow), putamen (green) and caudate (red) were 84 (range, 64–101), 61 (range, 49–80), 165 (range, 130–197), 211 (range, 165–240) and 105 (range, 80–138), respectively. The median voxel numbers of the frontal NAWM (solid black) and the occipital NAWM (dashed black) were 167 (range, 133–198) and 75 (range, 62–91), respectively