MRI in the management of MS

Abstract

Measures derived from conventional magnetic resonance imaging (MRI), including the number of active lesions, as well as the overall burden of T2-hyperintense and T1-hypointense lesions, and brain volume, have clear advantages over clinical assessment, including that they are more objective and more sensitive to multiple sclerosis (MS) related changes. For these reasons, conventional MRI has been incorporated into the diagnostic workup of patients with clinically isolated syndromes who are at risk of developing MS, and it is always recommended in patients with definite MS to monitor the course of the disease. Even though no standardized guidelines exist, follow-up brain MRI is advised whenever new diagnostic questions arise or new neurological symptoms develop, especially if suggestive of comorbid conditions. Patients about to start a new treatment or to change treatment should undergo a brain MRI scan. This MRI scan should then be repeated after 6–12 months to assess the effectiveness of the treatment regimen. In addition, conventional MRI-derived end-points have been used as primary and secondary outcome measures for monitoring MS clinical trials. The rationale for using conventional MRI metrics as surrogates for clinical outcomes is that the efficacy of a treatment in reducing relapses can be predicted at a trial level by its capacity to reduce active MRI lesions. In this context, the most widely used conventional MRI measures are those reflecting disease activity (new or enlarged T2 lesion counts, enhancing and new gadolinium-enhancing lesion counts, enhancing lesion volume measurement) and accumulated disease burden (T2 lesion load assessment). In the near future, it is likely that novel MR markers of MS evolution will be offered by non-conventional techniques and ultra-high field scanners.