ENHANCED AND UNENHANCED MR WITH MAGNETIZATION-TRANSFER IN MULTIPLE-SCLEROSIS

PURPOSE: To evaluate the use of magnetization transfer and the apparen t enhancement of lesions on contrast-enhanced MR images in patients wi th multiple sclerosis. METHODS: Contrast-enhanced T1-weighted spin-ech o MR images obtained in 20 patients with relapsing-remitting multiple sclerosis, with and without magnetization transfer, were evaluated to determine the number of enhancing plaques. Comparison was made with un enhanced T1-weighted magnetization transfer images, Contrast-to-noise ratios were obtained for these lesions on both the enhanced and unenha nced magnetization transfer T1-weighted spin-echo MR images. RESULTS: Ten plaques were considered enhancing only when the enhanced magnetiza tion transfer T1-weighted images (11% or more) were used; however, the y were all hyperintense on unenhanced T1-weighted magnetization transf er images. The contrast-to-noise ratios of these lesions were 16.52 fo r the enhanced images and 15.65 for the unenhanced images. The two val ues were not statistically different. CONCLUSIONS: In patients with mu ltiple sclerosis, examination with contrast-enhanced magnetization tra nsfer MR images alone may overestimate the number of enhancing plaques .