Region-of-interest placement. Transverse b = 0 s/mm2 images of a healthy control (multi-repetition single-shot echo-planar sequence; section thickness of 3 mm with no gap; 25 gradient directions; b = 1000 s/mm2; TR/TE = 15,000/82.1 ms; 1 average; FOV of 240 × 240 mm2; matrix of 128 × 128; voxel size of 1.8 × 1.8 × 3.0 mm3). Circular regions of interest are placed in the CWM (A), the CP and HI (B), the TH (C), the GP (D), and FWM and POWM (E).