PT - JOURNAL ARTICLE AU - J F Hiehle, Jr AU - R I Grossman AU - K N Ramer AU - F Gonzalez-Scarano AU - J A Cohen TI - Magnetization transfer effects in MR-detected multiple sclerosis lesions: comparison with gadolinium-enhanced spin-echo images and nonenhanced T1-weighted images. DP - 1995 Jan 01 TA - American Journal of Neuroradiology PG - 69--77 VI - 16 IP - 1 4099 - http://www.ajnr.org/content/16/1/69.short 4100 - http://www.ajnr.org/content/16/1/69.full SO - Am. J. Neuroradiol.1995 Jan 01; 16 AB - PURPOSE To define the relationship between magnetization transfer and blood-brain-barrier breakdown in multiple sclerosis lesions using gadolinium enhancement as an index of the latter. METHODS Two hundred twenty lesions (high-signal abnormalities on T2-weighted images) in 35 multiple sclerosis patients were studied with gadolinium-enhanced spin-echo imaging and magnetization transfer. Lesions were divided into groups having nodular or uniform enhancement, ring enhancement, or no enhancement after gadolinium administration. For 133 lesions, T1-weighted images without contrast enhancement were also analyzed. These lesions were categorized as isointense or hypointense based on their appearance on the unenhanced T1-weighted images. RESULTS There was no difference between the magnetization transfer ratio (MTR) of lesions as a function of enhancement. MTR of hypointense lesions on unenhanced T1-weighted images was, however, lower than the MTR of isointense lesions. CONCLUSION We speculate that diminished MTR may reflect diminished myelin content and that hypointensity on T1-weighted images corresponds to demyelination. Central regions of ring-enhancing lesions had a lower MTR than the periphery, suggesting that demyelination in multiple sclerosis lesions occurs centrifugally. In addition, the short-repetition-time pulse sequence seems useful in the evaluation of myelin loss in patients with multiple sclerosis.