simDRIFT – An open-source software package for massively parallel simulation of DWI experiments on biophysically accurate tissue systems.

Motivation: The software encompassed by this abstract, which we call simDRIFT, fulfills a presently unmet need by allowing for mesh-free Monte Carlo simulations of DWI that unify researchers' needs for computational performance and biophysical realism with easy-to-use and configurable open-source software. Goal(s): simDRIFT aims to provides for rapid and flexible Monte-Carlo simulations of Pulsed Gradient Spin Echo (PGSE) Diffusion-Weighted Magnetic Resonance Imaging (DWI) experiments. Approach: We compared the performance of simDRIFT against other open-source DWI simulators on identical voxel geometries. Results: Our results show that simDRIFT achieves orders of magnitude improved performance relative to other simulators, especially for large resident spin ensemble sizes. Impact: The performance gains achieved by simDRIFT support its aim to provide a customizable tool for the rapid prototyping of diffusion models, ground-truth model validation, and in silico phantom production.