In-vivo measurements of axon radius and density in the corpus callosum using anomalous diffusion from diffusion MRI

Abstract

Axon radius and packing density provide information on the role and performance of white-matter pathways. MRI researchers have tried to measure axon radius, however, they assumed the radius of axons follows a gamma distribution or a single axon radius was considered. From diffusion-weighted data, we mapped axon radii and packing density in the corpus callosum by fitting the parameters of the space fractional Bloch-Torrey anomalous diffusion model. We were able to calculate axon radii and packing density without any assumptions of axon radius. We found the values of axon radii to be in good agreement with previous findings