Ultra-high b radial diffusion-weighted imaging signals can be obtained from a selected portion of a nervous system of a subject. At least two ultra-high b radial diffusion-weighted imaging signals for the selected portion of the nervous system of the subject can be compared. The comparison is indicative of changes in the integrity or intactness of a bundle of axons within the selected portion of the nervous system of the subject.
Methods and systems of evaluating axonal loss and demyelination