Clinical-MRI correlations in the secondary progressive phase of MS: lessons from the treatment trials

Conventional MRI techniques are sensitive to detect MS lesions and their change overtime. In relapsing-remitting MS correlations with clinical measures are weak suggesting a pathological heterogeneity of these lesions. There are less data available in secondary progressive phase of the disease. The best source for clinical MRI correlations analysis is the placebo arm of the published interferon beta trials. This review presents the main clinical-MRI findings from these trials then focuses on recent promising observations obtained with non conventional MRI techniques in SP MS patients.