SERIAL MAGNETIZATION-TRANSFER RATIOS IN GADOLINIUM-ENHANCING LESIONS IN MULTIPLE-SCLEROSIS

The magnetisation transfer (MT) ratio of eight multiple sclerosis lesi ons has been studied serially. Initially, when the lesions showed gado linium enhancement, there was a marked reduction in their MT ratio com pared with normal white matter. Follow-up a mean of 11 months later (r ange 3-23 months), when the lesions no longer enhanced, revealed a con sistent and usually marked recovery of the MT ratios towards normal. T he MT ratio is thought to reflect the structural integrity of tissues with an important contribution from myelin and axons. MT imaging is a promising tool for elucidating pathophysiology and monitoring treatmen t in multiple sclerosis.