Whole brain high angular resolution diffusion images (HARDI; Frank, 2001) were acquired along 61 noncollinear directions including a b = 0 reference image (TE/TR = 93/10,900 ms, FOV = 240 mm, matrix = 128 × 128, 34 contiguous slices, 3 mm slice thickness, b-value = 1500 s/mm2). Two field maps were collected for unwarping to correct for signal loss and geometric distortion due to B0 field inhomogeneities (Andersson and Skare, 2002; Jezzard and Balaban, 1995).
