Characterization of White Matter Lesions in Multiple Sclerosis using Proton density and T1-relaxation Measures

Motivation: There is a limited understanding of the lesion heterogeneity in multiple sclerosis (MS), which needs to be investigated through different imaging techniques. Goal(s): To characterize MS lesions using proton density (PD) and T1-relaxation maps. Approach: PD and T1 data were generated for 20 relapsing-remitting MS patients. Lesions were voxel-wise divided into high PD regions and the remaining lesional tissue. Clinical scores were correlated with total lesion volume, volumes of high PD regions and high T1 regions. Results: Lesions with high PD exhibited highest probability of occurrence at the boundary of lateral ventricles and likely represent chronic lesions with significant local tissue rarefaction. Impact: Proton density and T1-relaxation maps act as an essential complement to the conventional clinical sequences and could serve as a new biomarker for assessing tissue damage in white matter lesions in relapsing-remitting multiple sclerosis patients.