大脑中动脉闭塞患者侧支循环与脑灌注研究

Studies of collateral circulation and cerebral blood perfusion in patients with middle cerebral artery occlusion

目的探讨大脑中动脉(MCA)闭塞患者脑侧支循环建立情况及其对脑灌注的影响。方法 46例单侧MCA闭塞患者,均行320排CT血管成像(CTA)联合CT灌注成像(CTP)检查,根据侧支循环分布状况分为侧支循环丰富组和侧支循环减少组,获取双侧MCA供血区的各项脑灌注参数值,即局部脑血流量(cerebral blood volume,CBV)、局部脑血容量(cerebral blood flood,CBF)、达峰时间(time to peak,TTP)及平均通过时间(mean transit time,MTT),用Rcbv、Rcbf、Rttp、Rmtt表示患侧与健侧各灌注参数的比值。对比分析健患两侧的脑灌注差异及两组患者脑灌注的不同。结果相比健侧,患侧MCA供血区TTP明显延长(P<0.05),CBV、CBF略升高(P<0.05),MTT略延长(P>0.05)。侧支丰富组Rcbv、Rcbf均高于侧支减少组(P<0.05),Rmtt低于侧支减少组(P<0.05),Rttp高于侧支减少组(P>0.05)。结论丰富的脑侧支循环可以有效地改善闭塞MCA远端缺血区脑组织的血流灌注。

Objective To explore collateral circulation in patients with middle cerebral artery（ MCA） occlusion and its effects on cerebral blood perfusion. Methods 320 row CT angiography（ CTA） combined with CT perfusion imaging（ CTP） were performed in 46 patients with unilateral MCA occlusion. According to the distribution of collateral circulation,46 patients were divided into abundant collateral circulation group or collateral circulation reduced group. Each perfusion parameters＇ value at the supply area of MCA,including regional cerebral blood volume（ CBV）,cerebral blood flood（ CBF）,time to peak（ TTP） and mean transit time（ MTT）,were then achieved. Calculate each parameter ratios of side-to-side aaccording to the hypofusion areas while haven＇t didn＇t developed to infarct（ Rcbv,Rcbf,Rttp,Rmtt）. Compared and analyzedsis the blood perfusion（ BP） on either side of braian and the difference of BP between two groups. Results TTP at the hypofusion areas extended obviously,CBV and CBF increased slightly compared with the contralateral areas,all with statistically significant difference（ P 〈0. 05）,while MTT extended slightly（ P 〈0. 05）. Abundant collateral circulation group had higher Rcbv and Rcbf（ P 〈0. 05）,shorter Rmtt（ P 〈0. 05） and longer Rttp（ P 〈0. 05） than that of collateral circulation reduced group. Conclusion Abundant cerebral collateral circulation can effectively improve the blood perfusion of ischemic brain tissue where MCA is occluded.