超急性期脑梗死CT灌注图中缺血半暗带的定位及病理基础的实验研究

The location and pathology of penumbra of hyperacute cerebral infarction in CT perfusion map

目的 研究缺血半暗带CT灌注图表现、病理基础及判定依据。方法 选新西兰白兔 42只 ,随机分组并制作脑缺血模型 ,分别于术后 0 .5、1、2、3、4、6h进行CT灌注扫描 ,测量并计算缺血区rCBF、相对面积。取兔脑组织进行病理观察。结果 缺血区rCBF随缺血时间延长不断下降。缺血中心区在缺血 4h前出现细胞水肿表现 ,4h后出现细胞核固缩等不可逆转变表现 ;边缘区为细胞水肿表现。结论 在CTPI图上缺血边缘区和缺血 4h内的中心区是可以恢复的缺血半暗带组织。

Objective To study the appearance and pathological changes of penumbra of superacute cerebral infarction in CT perfusion maps. Methods Acute cerebral ischemia models were presented in 42 New Zealand rabbits by obstructing the unilateral middle cerebral artery. Dynamic scans with venous bolus injection of contrast were performed at 0.5, 1, 2, 3, 4, 6 h respectively after operation. The rCBF of the interesting regions were calculated. The relative ischemic areas were measured and calculated. After every intervals of CT scan, cerebral tissues were obtained and were observed by photomicroscope and electron microscope. Results Between 0.5-6 hours after operation, the rCBF of ischemic areas decreased gradually with time after ischemia. The pathology showed that the cell edema could be observed on the ischemic cores within 4 hours after ischemia, and cell karyopycnosis could be found 4 hours after ischemia. The cell edema could only be observed on peri-ischemic areas. Conclusion Peri-ischemic areas and ischemic cores in perfusion maps within 4 hours after ischemia are viable penumbra tissues.