Fig. 2.

Longitudinal GM atrophy. (a) On the left side, the computation of longitudinal GM volume variations is illustrated for an arbitrary person with multiple sclerosis and selected axial slices of the right exterior cerebellum. Specifically, superimposed on the native anatomical T1-weighted images of this patient, red (green) areas highlight voxels classified as right exterior cerebellum at T0 (T1) by the procedure used for volume computation in our analyses. Yellow areas were classified as right exterior cerebellum voxels at both time points. (b) Regions with significant longitudinal GM volume reductions across pwMS. In all subgraphs in (b), the regional volumes were corrected for covariates of no interest. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)