Longitudinal Multiparametric Quantitative MRI Evaluation of Acute and Chronic Multiple Sclerosis Paramagnetic Rim Lesions

Multiple sclerosis (MS) paramagnetic rim lesions (PRLs) are markers of chronic active biology and exhibit complex iron and myelin changes that may complicate quantification when using conventional MRI approaches. To conduct a multiparametric MRI analysis of PRLs. Retrospective/longitudinal. Ninety-five progressive MS subjects with at least one persistent PRL who were enrolled in the CONSONANCE trial. 3-T/Susceptibility-weighted, T1-weighted, T2-weighted, and fluid-attenuated inversion recovery. Acute/chronic PRLs and non-PRLs were measured at screening, 24, 48, and 96 weeks using quantitative magnetic susceptibility (QS), R2*, and standardized T1w/T2w ratio (sT1w/T2w). PRL analyses were performed for whole lesion, core, and rim. The correlations between PRL core and rim sT1w/T2w, QS, and R2* were assessed. Linear mixed models. A P-value