Fig. 1. Benefiting from advances in microscopy techniques and from increases in computational power, the research focus of diffusion simulations has gradually switched to 3-dimensional tissue microgeometries.

Realistic white matter axons in (Lee et al., 2020b) are examples of voxelized simulation substrates used in RMS. The figure is adapted from (Chin et al., 2002; Xu et al., 2018; Nguyen et al., 2018; Palombo et al., 2019; Lee et al., 2020b) with permission from Wiley, Elsevier, and Springer Nature.