The numerical simulation of the diffusion MRI signal arising from complex tissue micro-
structures is helpful for understanding and interpreting imaging data as well as for designing
and optimizing MRI sequences. The discretization of the Bloch-Torrey equation by finite
elements is a more recently developed approach for this purpose, in contrast to random walk
simulations, which has a longer history. While finite element discretization is more difficult to
implement than random walk simulations, the approach benefits from a long history of …