Bimonthly assessment of magnetization transfer magnetic resonance imaging parameters in multiple sclerosis: a 14-month, multicentre, follow-up study.

This study was performed to assess the temporal evolution of damage within lesions and the normal-appearing white matter, measured using frequent magnetization transfer (MT) MRI, in relapsing—remitting multiple sclerosis (RRMS). The relationship of MT ratio (MTR) changes with measures of lesion burden, and the sample sizes needed to demonstrate a treatment effect on MTR metrics in placebo-controlled MS trials were also investigated. Bimonthly brain conventional and MT MRI scans were acquired from 42 patients with RRMS enrolled in the placebo arm of a 14-month, double-blind trial. Longitudinal MRI changes were evaluated using a random effect linear model accounting for repeated measures, and adjusted for centre effects. The Expanded Disability Status Scale (EDSS) score remained stable over the study period. A weak, but not statistically significant, decrease over time was detected for normal-appearing brain tissue (NABT) average MTR (—0.02% per visit; p = 0.14), and MTR peak height (—0.15 per visit; p = 0....