Multiple sclerosis: diagnostic optimism. (use of magnetic resonance imaging) (Editorial)

How magnetic resonance imaging has advanced understanding and research

Great strides have been made in our understanding of multiple sclerosis in the past decade. This new knowledge comes from experimental studies into the mechanism of immune mediated damage in the central nervous system and from magnetic resonance imaging.

The first step was the recognition that abnormalities in the brain in multiple sclerosis are easily identified by magnetic resonance imaging and that the lesions shown by the technique correspond with the plaques within the nervous system.[1-3] Soon it became clear that there was often a remarkable waxing and waning in size of the areas of abnormality over a matter of weeks.[4] Moreover, when the enhancing agent gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) was combined with magnetic resonance imaging some lesions became enhanced while others did not.[5-6]

These observations became understandable after frequent serial scanning in patients and a comparison of the results with the findings in allergic encephalomyelitis in animals and necropsy studies. Enhancement has been shown to correspond with regions of focal increase in permeability of the blood-brain barrier in association with inflammation.[7-8] Quantitative magnetic resonance methods have been used to study the nature of the "disappearing" element in the lesion and the structure of the residual …