Magnetic resonance imaging in the diagnosis and follow-up of patients with multiple sclerosis.

Magnetic resonance imaging (MRI) has had a major impact on the diagnosis of multiple sclerosis (MS). In addition serial MRI studies help to reveal a new aspect of measurable activity in MS. The degree of activity shown by serial MRI studies is considerably greater than the degree of activity indicated by history and physical examination. In addition, the extent of the MRI abnormalities can be measured by outlining the lesions and summing the areas of abnormality slice by slice. In the future careful, however, clinical follow-up studies must be done in order to identify the prognostic implications of these MRI data. At this time MRI evaluation techniques are considered a necessary adjunct method of assessment of disease activity for MS therapeutic trials. MRI methods are complementary to clinical methods and measure an index of extent of disease that is undetectable to clinical methods.