[Contribution of nuclear magnetic resonance imaging in multiple sclerosis].

Conventional MRI has become essential in the field of multiple sclerosis (MS). It reveals brain injury in visualising focal lesions of demyelination of the white matter, damage of the blood-brain barrier, and tissue loss within the lesions. These parameters are now used for an early diagnosis and for assessing the efficacy of new therapies. For years, neuroimaging research groups have been developing MRI techniques to get more sensitive and specific parameters of brain injury. Such techniques provide information on the extent of atrophy (volume, brain thickness), the metabolism (MR spectroscopy), the tissue structure (magnetization transfer and diffusion) and the compensation processes (functional MRI) of the brain. They lead to new approaches for analysing the pathophysiological processes at work in MS and their course in time.