Hypointense and hyperintense lesions on magnetic resonance imaging in secondary-progressive MS patients

Cranial magnetic resonance imaging (MRI) is widely used to monitor disease activity in clinical trials in multiple sclerosis (MS). The purpose of this study is to examine lesion burden as determined from hypointense regions o n postcontrast T1-weighted scans (or black holes), and lesion burden on con ventional T2-weighted scans, from a cohort of secondary progressive MS pati ents who participated in a placebo-controlled, randomized, double-blind cro ss-over trial assessing the therapeutic efficacy of cladribine. T2 lesion v olumes and black hole volumes are approximately normal distributed when log -transformed, and are highly correlated (adjusted R-2 = 0.63). Changes in c linical scores could be predicted with a reasonable degree of precision fro m baseline scores and changes in T2 lesion volumes (adjusted R-2 values 0.5 2-0.7). Stratification schemes for clinical trials should include the acute proportion of the disease (enhancing T1 lesions), degree of permanent dama ge (black holes), and T2 lesion volume.