POSITRON EMISSION TOMOGRAPHY, MAGNETIC-RESONANCE-IMAGING AND PROTON NMR-SPECTROSCOPY OF WHITE-MATTER IN MULTIPLE-SCLEROSIS

Objective. To assess characteristics of MS lesions and normal appearin g white matter (NAWM) with various imaging modalities. Glucose metabol ism was investigated with FDG-PET, metabolite concentration with proto n NMR spectroscopy and lesion detection with routine brain MRI. Method s: Thirteen patients were studied in a stable phase of their disease, and two during on acute episode. Nine healthy volunteers served as con trols. Results: Three patients had a normal brain MRI, IZ had typical lesions. MR images were registered to the PET planes. Lesions and cont ra-lateral control areas were analyzed 10/15 lesions showed relative h yper-metabolism and 2 hypo-metabolism. NAA concentration was significa ntly decreased in both lesions and NAWM. Conclusion: In stable MS, mos t large lesions have a relatively increased glucose utilization and de creased NAA concentration. NAWM showed a significantly decreased NAA c oncentration compared to healthy subjects, but no difference in glucos e metabolism. Active lesions in acute MS are also hyper-metabolic This finding opens a new window on the classification of white matter lesi ons based on glucose utilization.