Magnetic resonance imaging techniques to define and monitor tissue damage and repair in multiple sclerosis

Conventional magnetic resonance imaging (cMRI) has greatly improved our ability to diagnose multiple sclerosis (MS) and to monitor its evolution, either natural or modified by treatment. cMRI-derived measures have indeed shown several advantages over clinical assessment, including their more objective nature and increased sensitivity to MS-related changes. Nevertheless, the magnitude of the relationship between cMRI measures of disease activity or burden and the clinical manifestations of the disease is weak. Several factors are likely to be responsible for this clinical/MRI discrepancy, including the poor specificity of dual-echo scans with regard to the heterogeneous pathological substrates of individual lesions and the inability of T2-weighted images to delineate tissue damage occurring in the normal-appearing white matter (NAWM) and grey matter (GM).