Dynamic susceptibility contrast MR imaging of plaque development in multiple sclerosis: Application of an extended blood-brain barrier leakage correction

Since the pathogenesis of multiple sclerosis (MS) lesions is not yet fully understood, we investigated the potential of dynamic susceptibility contras t (DSC) magnetic resonance (MR) perfusion imaging for a better characteriza tion of lesion pathology. Twenty-five MS patients were examined on a 1.5 T scanner. A single dose of gadolinium (Gd)-DOTA contrast agent was injected, and echoplanar images were acquired every 0.5 seconds for 1 minute. From t he signal intensity-versus-time curves, the relative cerebral blood volume (rCBV) was evaluated for regions in plaques and in gray and white matter. T he rCBV calculated for acute, Gd-enhancing plaques was corrected for the ef fects of blood-brain barrier leakage, using a new correction algorithm. Acu te plaques had significantly higher blood volumes than normal-appearing whi te matter (P < = 0.01), Chronic plaques that appeared hypointense on T,weig hted images had lower rCBV than T-1-isointense plaques (P < = 0.03), Our re sults indicate that the acute phase in MS is accompanied by vasodilation, I n later stages of gliosis, the perfusion decreases with increasing axonal i njury, Although the DSC technique is less sensitive than conventional MR im aging, the information provided is essentially different from that obtained with any other MR method. (C) 2000 Wiley-Liss, Inc.