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目的探讨血肿周围组织脑水肿形成机制及其与局部脑血流变化间的关系,为脑出血临床救治提供实验基础。方法雄性大鼠70只,随机数字抽样法分为注血组和对照组,分别将40μl新鲜自体血或生理盐水通过微量注射泵注入大鼠脑右侧尾状核制备脑出血模型,利用CT灌注成像对大鼠脑出血模型进行动态增强扫描,通过计算机辅助脑灌注成像软件制作大鼠脑CT灌注参数图,对血肿周围局部脑血流量(regional cerebral blood flow,rCBF)、局部脑血容量(regional cerebral bloodvolume,rCBV)和对比剂平均通过时间(mean transit time,MTT)脑灌注参数进行相对值(病侧/健侧)测量,并与血肿周围脑组织水含量进行相关性分析。结果大鼠脑注血后血肿周围组织存在低灌注梯度,血肿周围rCBF呈波动性改变,注血后1h rCBF降至最低,以后逐渐回升,分别于注血后6h和24h2次回升至峰值,并随后再度下降;血肿周围rCBV在注血后1h降至最低,随后逐渐增加,并于注血后24h增加至峰值;血肿周围脑组织水含量在注血后24h最高,并延续至72h;血肿周围脑组织水含量与血肿边缘区rCBV具有明显相关性,r=0.372(单侧),P<0.05。结论血肿周围组织脑水肿的形成是血脑屏障破坏、细胞毒性水肿及渗透性活性物质共同作用的结果,脑出血早期rCBF下降以及rCBV代偿性增加在脑出血血管源性脑水肿形成中发挥着重要作用,CT灌注成像是活体下研究血肿周围脑血流变化与脑水肿形成机制较为理想的方法。
Objective To explore the mechanism of cerebral edema around the hematoma and its relationship with the changes of regional cerebral blood flow, and to provide experimental basis for the clinical treatment of cerebral hemorrhage. Methods Seventy male Sprague-Dawley rats were randomly divided into two groups: injection group and control group. 40 μl of fresh autologous blood or normal saline were injected into the right caudate nucleus of rat brain through a microinjection pump to prepare cerebral hemorrhage model. CT perfusion Imaging Dynamic enhancement scan of intracerebral hemorrhage model in rats was made by computer-assisted cerebral perfusion imaging software to make CT perfusion parameter map of rat brain. The effects of regional cerebral blood flow (rCBF), regional cerebral blood volume cerebral blood volume (rCBV) and contrast transit time (MTT), respectively. The correlations between the cerebral blood volume and the surrounding blood samples were analyzed. Results There was a low perfusion gradient in the perihematomal brain tissue around the rats after injection. The rCBF fluctuated around the hematoma, and the rCBF decreased to the lowest level at 1 hour after the injection of blood. The rCBF gradually rose back to the peak at 6 h and 24 h after injection Then decreased again; rCBV around hematoma decreased to a minimum at 1 hour after injection, and then gradually increased and reached the peak at 24 hours after injection; water content in brain tissue around hematoma was the highest at 24h after injection and continued to 72 hours; There was a significant correlation between brain water content and rCBV in hematoma marginal zone, r = 0.372 (unilateral), P <0.05. Conclusion The formation of cerebral edema around the hematoma is a result of the destruction of the blood-brain barrier, cytotoxic edema and permeable active substance. The decrease of rCBF and the compensatory increase of rCBV in the early stage of ICH play an important role in the formation of vasogenic brain edema The important role of CT perfusion imaging in vivo is to study the changes of cerebral blood flow around the brain and brain edema formation mechanism is the ideal method.