Abstract

Purpose To investigate in vivo the spatial specificity of the interdependence between intracortical and white matter (WM) pathologic changes as function of cortical depth and distance from the cortex in multiple sclerosis (MS), and their independent contribution to physical and cognitive disability. Materials and Methods This study was institutional review board-approved and participants gave written informed consent. In 34 MS patients and 17 age-matched control participants, 7-T quantitative T2* maps, 3-T T1-weighted anatomic images for cortical surface reconstruction, and 3-T diffusion tensor images (DTI) were obtained. Cortical quantitative T2* maps were sampled at 25%, 50%, 75% depth from pial surface. Tracts of interest were reconstructed by using probabilistic tractography. The relationship between DTI metrics voxelwise of the tracts and cortical integrity in the projection cortex was tested by using multilinear regression models. Results In MS, DTI abnormal findings along tracts correlated with quantitative T2* changes (suggestive of iron and myelin loss) at each depth of the cortical projection area (P