Magnetic resonance (MR) imaging techniques that measure cerebral perfusion have become increasingly important. It is due to the limitation of other imaging modalities (single photon emission computed tomography, SPECT ; positron emission tomography, PET etc.) and conventional MR imaging to detect cerebral perfusion, and its ability to identify and quantitate changes in cerebral perfusion may have a substantial effect on both the diagnosis and treatment of cerebrovascular disease. We evaluated the cerebral perfusion and arterial recanalization of large territorial infarction in acute, subacute and chronic stage by MR image and MR angiography and tried to correlate with motor improvement. Twenty six patients with large territorial infarction of middle cerebral artery (MCA, n=23) or posterior cerebral artery (PCA, n=3) were included in this study. In conjunction with conventional brain MR imagings, thirty-four dynamic susceptibility contrast-enhanced MR imagings (DSC-MRI) and MR angiography were performed in acute (< lweek, n=22), subacute (1-3 weeks, n=7), and chronic (3-5weeks, n=5) stages of cerebral infarction. Regional cerebral blood volumes (rCBVs) were calculated on a pixel-by-pixel basis and rCBV images were generated. Perfusion of infarcted areas were compared to contralateral normal regions by rCBV ratio (rCBV of infarcted area/that of contralateral), and arterial recanalization of infarcted area were investigated by MR angiographies. Motor power of the hemiparetic side of the patients was observed during the first 5 weeks after the stroke onset. The rCBVs of ischemic regions increased in subacute period than acute period and decreased again in chronic period (p<0.01, Kruskal Wallis one-way ANOVA), and these patterns were also correlated with visual findings of rCBV images. Recanalization of occluded arteries was found on MR angiagraphy in 3 patients (13.69.1) in acute, 6 patients (85.7%) in subacute and 4 patients (80.0%) in chronic infarction. The increase of "rCBV ratio" was more frequently seen in recanalization than no recanalization cases but we could not statistically analyze the difference due to small size of sample. In MCA infarctions, there is no significant relationship between rCBV with motor improvement during first 5 weeks after the onset. DSC-MRI is noninvasive, more widely available than other functional images (SPECT and PET) and easier to perform in an emergency setting. By providing information about hemodynamics, which is not available with conventional T1 or T2-weighted images, DSC-MRI will be helpful in describing the pathaphysiologic characteristics of stroke.
Angiography ; Arteries ; Blood Volume ; Brain ; Cerebral Infarction* ; Diagnosis ; Emergencies ; Hemodynamics ; Humans ; Infarction ; Magnetic Resonance Imaging ; Middle Cerebral Artery ; Perfusion* ; Positron-Emission Tomography ; Posterior Cerebral Artery ; Stroke ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon