T1mapping and MPRAGE for the characterisation of heterogeneous paramagnetic rim lesions and their clinical importance in MS

Motivation: Differentiation of Paramagnetic Rim Lesions, based on T1 values, could allow clinical stratification of patients. Goal(s): To investigate PRL heterogeneity with quantitative T1 and normalised MPRAGE and the resulting impact on clinical outcomes. Approach: White Matter lesions were segmented and categorised based on visual confidence of paramagnetic rim visibility and their T1 values. RF analyses was used to reveal impact of lesion types on clinical disability. Results: Visibility of Rim+ lesions is correlated with increased T1 values. In a Random Forest Model, T1-derived long-T1 Rim+ lesions and number of short-T1 Rim+ lesions could predict clinical disability and clinical progression in next 12 months. Impact: Characterisation of PRL heterogeneity, not only with advanced-quantitative imaging techniques but also with clinically available sequences, allows a better understanding of a patient's current clinical disability and progression over the next twelve months.