Discovering white matter structure beyond anisotropy maps with diffusion MRI
Diffusion mri (dmri) is the only method that allows in vivo segmentation of white matter (wm) fasciculi and assessment of their integrity, based on the water diffusion anisotropy caused by highly ordered bundles of axons [5, 6]. It can therefore be used to study wm decline: loss of integrity and tract thinning. Their disambiguation given the mri data is not trivial. We show that it is possible to obtain reasonable estimates of both tract volume (on a sub-voxel level) and diffusivity parameters linked to the well being of axonal bundles using a plausible spatial coherence assumption.