Prediction of Impending Hemorrhagic Transformation in Ischemic Stroke Using Magnetic Resonance Imaging in Rats

摘要: Background and Purpose —Hemorrhagic transformation (HT) of ischemic brain tissue may occur in stroke patients either spontaneously or after thrombolysis. A method to assess the risk HT would improve safety thrombolytic therapy. As a means predicting HT, we investigated role contrast-enhanced MRI at acute time points rat middle cerebral artery occlusion model with reperfusion. Methods —Intraluminal suture was used produce transient ischemia male Wistar rats (n=11). Reperfusion performed by withdrawal occluding filament 2 (n=4), 3 (n=6), 4 (n=1) hours. studies were before reperfusion use conventional T1-weighted imaging, without gadolinium (Gd-DTPA) contrast agent, T2-weighted imaging. Follow-up histological obtained 24 hours. Results —Petechial hemorrhage occurred hours 9 11 animals. All animals showed swelling cellular death throughout region hyperintense preoptic area became visible Gd-DTPA injection within minutes subsequent HT. showing enhancement subsequently developed petechial (or died) In these animals, statistically significant differences signal intensity ( P =.0005) between ipsilateral enhancing homologous contralateral detected on post–Gd-DTPA There also correlation =.01) rate uptake size area. Two did not enhance exhibit examination No abnormalities seen precontrast images shortly postcontrast reperfusion. Conclusions —The primary finding this study detection early parenchymal 82% reperfusion. Enhancement any detectable hemorrhage, suggesting that endothelial damage occurs gross infarction hemorrhage. Thus, suggest provide an prediction