目的探讨灌注加权成像 (perfusion weighted imaging，PWI) 评价侧支循环在椎基底动脉狭窄致后 循环缺血 ( p o s t e r i o r c i r c u l a t i o n ischemia,PCI)患者中的作用。方法 选取 2014年1月至2017年1月期间本院收治的 椎基底动脉狭窄致PCI患者76例作为病例 组，另选取无椎基底动脉狭窄的健康体检 者75例作为对照组，全部研究对象均采用 PWI检查。结果 病例组PWI检查呈低灌注 改变，对照组双侧大脑前中后动脉与颈内 动脉血管显示良好，血管腔畅通，血管壁 光滑完整。病例组微小动脉团显示、软脑 膜动脉显示与后交通动脉开放所占比例明 显高于对照组，两组比较差异具有统计学 意义(P<0.05)。与对照组比较，病例组 rMTT明显延长，rCBV、rCBF值明显降低， 两组比较差异具有统计学意义(P<0.05)。 PWI与DSA检查对椎基底动脉狭窄的检查符 合率94.74%。结论 PWI可准确评价侧支循 环在椎基底动脉狭窄致后循环缺血患者中 的代偿作用，了解缺血组织的血流动力学 状况，为治疗方案制定与预后评定中提供 指导意义，值得临床推广应用。

Objective To discuss the role in perfusion weighted imaging(PWI) evaluation of collateral circulation for patients with posterior circulation ischemia(PCI) induced by vertebral basilar artery stenosis. Methods 76 cases of patients with PCI induced by vertebral basilar artery stenosis treated from our hospital during the period of January 2014 and January 2017 were selected as case group, 75 cases of health physical examination without vertebral basilar artery stenosis were selected as control group, all study object were given PWI examination. Results PWI examination of the case group showed low perfusion change, and two-side cerebral anterior, middle and posterior arterial and internal carotid artery showed good results, vascular cavity was smooth and the vessel wall was smooth， intact. The proportion of microarterial shown, pial artery shown, posterior communicating artery patency of the case group were significantly higher than that in the control group, and the difference between the two groups was statistically significant (P<0.05). Compared with the control group, rMTT of the case group was significantly prolonged, rCBV and rCBF were significantly reduced, and the difference between the two groups was statistically significant (P<0.05). The coincidence rate of vertebral basilar artery stenosis between PWI and DSA examination was 94.74%. Conclusion PWI can accurately evaluate the compensatory function of collateral circulation for patients with PCIinduced by vertebral basilar artery stenosis, understand the status of ischemic tissues hemodynamics, offer significant guidance for treatment plan and prognosis evaluation, it is worthy of clinical popularization and application.