[Clinical usefulness of MRI in acute phase of spinal multiple sclerosis--influence of high-dose steroid therapy in acute phase].

Magnetic resonance imaging (MRI) is useful for detecting spinal cord lesions in multiple sclerosis (MS). In this study, we have examined MRI for 14 patients (26 cases) with clinically definite MS and investigated the correlations between neurological and MRI findings before and after high-dose corticosteroid therapy (pulse therapy). High signal intensity areas on T2-weighted images (T2WI) were found in 25 of 26 cases. In 22 cases spinal level of clinically suspected lesions were involved in these high intensity areas. T1-weighted images (T1WI) after intravenous gadolinium with diethylenetriamine pentaacetic acid (Gd-DTPA) were also obtained and in 12 of 17 cases before pulse therapy, the symptoms and enhancement of lesions correlated well. The symptoms regressed in all cases after pulse therapy, and high-intensity areas in T2WI became less distinct. Gd-DTPA enhanced areas disappeared in 6 cases and became smaller in 3 of 12 cases. Additional pulse therapy in 3 cases effectively diminished the enhanced areas in these cases. In one patient who had repeated pulse therapy, MRI showed no enhancement. In two other patients who continued on decreased steroid dose had relapses, pulse therapy was therefore started again, providing a good recovery both clinically and radiologically. The changes of MRI findings and clinical course suggest that the pathological changes in spinal MS may be caused not only by demyelination but also by parenchymal edema. Clinical and MRI concordance was significantly better with Gd-DTPA enhanced T1WI than the high-intensity areas in T2WI. Contrast enhancement gives more information about disease activity and the reaction to therapy.