CT灌注成像实时评价大鼠急性脑缺血再灌注模型

CT perfusion imaging evaluation on acute cerebral ischemic-reperfusion rat model

目的运用CT灌注成像对大鼠急性脑缺血再灌注模型进行实时评价。方法取36只Wistar大鼠,随机分为两组。用线栓法制作大鼠脑缺血再灌注模型,缺血组于梗塞后相应的时间点(1h、6h),再灌注组则于各个时间点灌注前后分别行CT灌注成像的检查,各组在进行CT灌注成像的检查前对大鼠进行神经功能评价,最后取大鼠的脑组织进行病理观察。结果缺血1h再灌注前后的相对脑血流量(relative cerebral blood flow,rCBF)变化明显,神经功能缺损基本恢复,缺血6h再灌注前后病灶边缘区rCBF变化明显,中心区则无变化,神经功能缺损部分恢复。病理学检查与以上结果相一致。结论线栓法制作大鼠脑缺血再灌注模型稳定,结合CT灌注成像检查能够及时进行筛选,为实验研究提供实时可靠信息。

Objective To evaluate the reliability of acute cerebral ischemic-reperfusion rat model by CT perfusion. Methods Acute cerebral ischemic-reperfusion models were presented in 36 Wistar rats by obstructing the unilateral middle cerebral artery. The rats were divided into 2 groups. Dynamic scans with venous bolus injection of contrast medium were performed at 1,6 h respectively after operation in ischemic group with SIEMENS Somatom Sensation 16 MSCT. In reperfusion group,dynamic scans with venous bolus injection of contrast medium were performed at 1 ,6 h respectively before and after reperfusion. The rCBF of the region of interest （ROI） were measured and calculated. Both groups were evaluated with neurological deficit score. After every intervals of CT scan, cerebral tissues were observed by photomicroscope and electron microscope. Results CT perfusion imaging could locate the ischemic focus during the acute phase. The changes of rCBF were more obvious in the ischemic-reperfusion team after 1 h than the areas of ischemic cores of those rats perfused after 6 h. The scores of neurologic impairment assessmen and the pathological changes were correlated with those phenomenon. Conclusion The method of making an acute cerebral ischemic-reperfusion model by obstructing the unilateral middle cerebral artery is very stable. If we can screen the stroke model with CT peffusion examination, the error caused by variance of model can be reduced. Thereby it provides a platform for researchers to investigate acute cerebral ischemia and reeirculation.