Diffusion Weighted MR Imaging in Evaluation of CNS Disease

Abstract

145 patients with a wide variety of CNS disease were studied. All patients had conventional spin-echo and diffusion weighted MR (b = 1000); 90% had perfusion studies and 15% had MR spectroscopy. Hyperintense lesions on diffusion weighted MR were identified in the following entities: acute stroke, CNS lymphoma, glioma, tumefactive MS, epidermoid cyst and acute dural sinus thrombosis with venous infarction. Hypointense lesions included the following: chronic infarct, arachnoid cyst, porencephalic cyst, and cystic or necrotic portions of gliomas and metastases.

MR spectroscopy showed elevated choline peak with neoplastic lesions and in tumefactive MS; elevated lactate peak was present with infarcts. There was decreased perfusion in infarcts. Diffusion weighted imaging is the most sensitive MR technique for detecting and differentiating acute infarction from TIA and other stages of infarction. Decreased diffusion was also observed in CNS lymphoma, glioma, and tumefactive MS; MR perfusion and spectroscopy may be helpful in further differentiating these entities.