To date, there is no biological test available with enough confidence to make alone a diagnosis of Multiple Sclerosis (MS). MS diagnosis criteria are then an association of clinical and para clinical criteria that allow an objective demonstration of dissemination of lesions in both time and space. Adapted MRI criteria from Barkhof have a good sensitivity and the best specificity to evaluate MS. 3 of 4 criteria are necessary: 1 gadolinium enhancing lesion or 9 T2 hyper intense lesions; at least 1 infratentorial lesion; at least 1 juxtacortical lesion; at least four periventricular lesions; NB: 1 spinal cord lesion can substitute for 1 brain lesion. News methods as spectroscopy, magnetization transfer, diffusion MRI and functional MRI complete results of conventional MRI and give new informations about physiopathology of MS demyelinating lesions.