Figure 6.

Simulated coincidence angles are shown for the whole brain slice with gradient schemes ‘original 6′ (a), ‘original 12′ (b), ‘original 21′ (c) and ‘original 92′ (d). The simulation is repeated 200 times by generating DW signals using the ‘true’ diffusion tensor with simulated random noise. The coincidence angle measures the difference in orientation between the major cone axis and the second eigenvector of the diffusion tensor (see Fig. 1b). As the number of gradient directions (i.e., angular resolution) increases, the directional coincidence increases (i.e., the coincidence angle decreases).