MRI: role in optimising treatment.

Magnetic resonance imaging (MRI) is an extremely sensitive diagnostic tool that provides us with highly detailed images of the living human brain. Since it was first applied to multiple sclerosis (MS) in clinical trials in the 1980s, MRI has become established as a reliable, sensitive and reproducible technique for studying the pathophysiology of this complex disease. It has provided a variety of surrogate measures for clinical trials, and continues to offer new methods for the detection and monitoring of the physical and chemical changes in the brains of living patients. The unique sensitivity of conventional MRI measures for detecting MS pathology has made MRI an attractive tool for optimising treatment in clinical practice for individual patients.