Diffusion MRI of white matter lesion dynamics in progressive multiple sclerosis

Motivation: It is unclear how white matter lesions evolve during the progressive stage of multiple sclerosis (MS). Goal(s): To measure four-month change in diffusion metrics within lesions of progressive MS patients. Approach: We compare diffusion changes within the lesions with those in the normal-appearing white matter (NAWM). Results: Diffusion metrics in the lesions generally follow opposite trajectories to those in the NAWM, often with greater magnitude. Impact: This work indicates that it may be desirable to monitor the progressive stage of MS by assessing diffusion changes within white matter lesions, rather than merely within the NAWM as is customary.