[Magnetic resonance imaging in multiple sclerosis. Sensitivity and correlation with the clinical picture]

The aim of imaging the brain in Multiple Sclerosis (MS) is to prove the dissemination of lesions, so critical for the diagnosis and so difficult to ascertain clinically. Our study included 21 patients with clinically definite (12) and probable (9) MS. A 21 patients underwent a neurological standard examination, a double-dose delayed CT scan and a Magnetic Resonance Imaging with a superconducting 0.5 Tesla magnet. Jointed slices were performed with a T2-weighted Spin-Echo sequence (TE 60, 120; TR 2000 msec). MRI detected 640 lesions in 20 patients while CT scan detected only 24 lesions in 9 patients. Technical limiting factors are discussed. Abnormalities in MRI were high-intense spots, blotches and streaks, located predominantly in the periventricular area. Capping lesions were common around the ventricular horns. "Plaques" were visualized in the posterior fossa. For each patient, the total surface of the lesions was calculated and was found to be related with the presence of lesions and with the cortical atrophy on CT scan. A correlation between the surface of lesions calculated by MRI and the disability scale was found especially in the group of patients with clinically proven cerebral lesions, while patients with predominantly spinal forms had a significantly lower surface of lesions. This finding could yield a new quantitative evaluation of the MS pathologic process which could be used to assess therapeutic efficacy.