COMPARISON OF 4 POTENTIAL MR PARAMETERS FOR SEVERE TISSUE DESTRUCTIONIN MULTIPLE-SCLEROSIS LESIONS

The purpose of this study was, first, to evaluate correlations between four potential magnetic resonance (MR) parameters for severe tissue d estruction in multiple sclerosis (MS) lesions. Second, to evaluate the effect of incidental magnetization transfer (MT) effect on hypointens e lesions in multislice T-1 spin echo (SE) imaging, In 49 lesions, fro m 10 MS patients, MT ratio (MTR), T-1 relaxation time, signal intensit y (SI) on T-1-weighted SE images normalized to normal-appearing white matter (NAWM), and SI normalized to cerebrospinal fluid (CSF) were mea sured, Differences in contrast of hypointense lesions were measured be tween single slice and multislice imaging. MTR correlated significantl y (p < .001) with longitudinal relaxation rates (1/T-1) (r = 0.84), SI normalized to NAWM (r = 0.78), and SI normalized to CSF (r = 0.75). T he degree of reduction in contrast, caused by multislice imaging, corr elated significantly with MTR of lesions (r = 0.60, p < .001), leading to reduction of hypointense lesion load (p < .01). We conclude that a ll four MR markers for severe tissue destruction are highly correlated when applied to selected hypointense lesions on T-1-weighted SE image s. Due to ''incidental'' off-resonance excitation, contrast and hypoin tense lesion load will be reduced in multislice T-1-weighted SE images . (C) 1997 Elsevier Science Inc.