Comparison of Perfusion- and Diffusion-weighted MRI in Acute Ischemic Stroke

J Korean Neurol Assoc > Volume 18(5); 2000 > Article

Journal of the Korean Neurological Association 2000;18(5): 535-543.

급성기 허혈성 뇌졸중 환자에서 관류 자기공명영상과 확산강조 자기공명영상의 비교

이준원, 변상진 ·김은주*·정은기*·이태규 ·장대일 ·정경천

경희대학교 의과대학 신경학교실,연세대학교 의과대학 진단방사선학교실*

Comparison of Perfusion- and Diffusion-weighted MRI in Acute Ischemic Stroke

Jun-Won Lee, M.D., Sang-Jin Byun, M.D., Eun-Ju Kim, M.S.*, Eun-Kee Jung, Ph.D.*, Te Gyu Lee, M.D., Dae-Il Chang, M.D., Kyung-Cheon Chung, M.D.

Department of Neurology, College of Medicine, Kyung Hee University, Seoul, Korea Department of Radiology, Yonsei University Medical College, Seoul, Korea*

Abstract

"Background : Perfusion imaging (PI) of magnetic resonance imaging (MRI) uses the signal loss that occurs during dynamic tracking of the first pass of intravenous paramagnetic contrast agent. Then different hemodynamic measure-ments can be calculated and displayed as perfusion maps. Diffusion-weighted imaging (DWI) measures diffusional movement of water molecules within the brain and it can identify acute ischemic injury or cytotoxic edema. We evalu-ated clinical usefulness of PI and DWI in acute ischemic stroke. Methods : Fifteen patients with clinical diagnosis of acute cerebral infarction were imaged with PI, DWI, and magnetic resonance angiogram (MRA) including FLAIR with-in 24 hours after onset. Comparisons were made between infarct volumes measured by DWI and PI using the parame-ters including relative mean transit time (rMTT) map, relative cerebral blood volume (rCBV) map, and relative cerebral blood flow (rCBF) map. Results : Two patterns were found. rMTT map in PI lesion is larger than in the DWI lesion (n=7/15), and rMTT map in PI lesion is the same size or smaller than in DWI lesion (n=8/15). The former pattern was shown in cases with severe stenosis or occlusion of the major cerebral artery (MCA, PCA, or ICA) on MRA. The majority of latter pattern was lacunes (n=6/8). Also, we found presence of infarction cores surrounded by hypoperfused areas in rMTT map in acute large-arterial territorial infarction. Conclusions : Perfusion- and Diffusion- weighted MRIs may be useful in differentiating large-arterial territorial infarction from lacunes. J Korean Neurol Assoc 18(5):535~543, 2000 Key Words : Perfusion MRI, Diffusion MRI, Acute ischemic stroke"