Dictionary of simulated tissue samples mimicking white matter

In order to go beyond current state-of-the-art analytical models for the local orientation distribution functions (ODFs), a simulator have been developed to generate white matter virtual tissues that are usable by diffusion MRI (dMRI) and/or 3D-Polarized Light Imaging (3D-PLI) simulations. These tissue simulators are referred to as the Microstructure Environment Designer with Unified Sphere Atoms (MEDUSA). MEDUSA enables the generation of highly detailed numerical white matter phantoms biomimicking realistic geometric fiber configurations at different levels of disorder. By this means, the influence of various geometrical parameters present in white matter — such as global angular dispersion, tortuosity, presence of Ranvier nodes, or beading — on the measurement signal can be investigated. With MEDUSA, we have generated the here provided dictionary of white matter phantoms to study the impact of the listed parameters on the extra-cellular perpendicular diffusivity frequency in dMRI by simulating the diffusion process within in the phantoms of increasing complexity. These models are geometrically generalized, therefore they can be used across species, e.g. human or rodents.