EVALUATION OF MULTIPLE-SCLEROSIS BY H-1 SPECTROSCOPIC IMAGING AT 4.1 T

The authors report on high-field (4.1 T) magnetic resonance H-1 spectr oscopic imaging studies on eight patients with relapsing remitting mul tiple sclerosis (mean expanded disability status scale (EDSS) 1.0) and eight normal controls. Using T-1-weighted imaging to determine lesion position, the authors found the ratios of choline/N-acetyl (NA) compo unds and creatine/NA were increased significantly in the multiple scle rosis (MS) patients relative to controls in lesioned tissue, adjacent to lesion, far removed from lesions as well as in periventricular tiss ue. The gray matter creatine/NA was mildly increased (P < 0.01) in the MS patients, whereas the elevated gray-matter ratio of choline/NA was of borderline significance (P = 0.13), A more detailed comparison of white-matter and mean gray-matter metabolite values indicates that cre atine is increased greatest in areas far from lesions. This is in cont rast to choline, which was greatest in lesions, and NA, which was smal lest in lesions. It is postulated that the creatine increase may refle ct an astrocytic (gliotic) or oligodendrocytic remyelinating process. The increased choline most likely reflects varying levels of inflammat ion and membrane turnover, whereas the NA decrease is representative o f axonal dysfunction or loss.