Multiple sclerosis: what have we learned from magnetic resonance imaging studies?

We review studies that have examined the relationship between magnetic resonance imaging findings and clinical disability, postmortem observations, and cognitive dysfunction in patients with multiple sclerosis. We also review the use of magnetic resonance imaging findings as an outcome measure in clinical trials assessing the efficacy of new therapeutic agents for the treatment of multiple sclerosis. More advanced applications of magnetic resonance imaging and their use in multiple sclerosis is addressed later in the article.