Godi C, et al. – This study was undertaken to assess whether a b–value of 3,000 s/mm2 (b3000) can improve visualisation of PML, or provide different structural information compared to 1,000 s/mm2 (b1000). The results validated that b3000 enhances visualisation of this important PML hallmark. Furthermore, b3000 partly reclassifies tissue from rim into core, and might provide potentially more accurate biomarkers of PML activity and prognosis.