目的 探讨64层螺旋CT脑灌注成像（CT perfusion，CTP）联合CT血管造影（CT angiography ，CTA）评价单侧大脑中动脉（middle cerebral artery，MCA）重度狭窄(闭塞)颅内外血管搭桥术后疗效的可行性。方法 46例拟行颅内外血管搭桥术患者，术前、后均行CTP及CTA检查。计算脑灌注参数图，对治疗前后脑灌注参数进行定量和定性对比分析。CTA图像采用VR、CPR及MIP重建方法显示桥血管的走行及吻合口。结果 46例 MCA重度狭窄（闭塞）患者，术后达峰时间（time to peak，TTP）、相对平均通过时间（relative mean transit time，rMTT）图上灌注异常区较术前减小，差异有统计学意义（P0.05）。CTA准确率96.5%。所有桥血管清晰显示，吻合口通畅。结论 CTP能够观察治疗前后脑灌注改善情况；CTA可以清楚地显示术后颅内外血管状态，两者相结合，为评价疗效提供可靠的影像学依据。

Objective To assess the curative effect of cerebral internal and external vascular bypass graft in patients with single middle cerebral artery(MCA) stenosis or occlusion by combining 64-row CT cerebral perfusion(CTP) with angiography(CTA). Methods Patients with middle cerebral artery stenosis or occlusion were recruited and underwent superficial temporal artery and middle cerebral artery(STA-MCA) bypass graft between March 2009 and Mar 2011. CTP and CTA examinations were performed in all patients before and after operation. The cerebral perfusion parameters were analyzed quantitatively and qualitatively. The origin, travel and anastomotic stoma of bypass grafts were evaluated by reconstructed CTA images. Results 46 patients were found with severe MCA stenosis or occlusion. The time to peak (TTP) and relative mean transit time(rMTT) images before therapy displayed the existence of perfusion delay. The relative cerebral blood flow (rCBF) and relative cerebral blood volume(rCRV) images did not change significantly. The decrease of TTP and rMTT after therapy was of statistical significance（P0.05）. In reconstructed CTA images, 82 bridge vessels were well displayed, including double bridges in 39 patients. The accuracy of CTA examination was 96.5%. All the bypass grafts were well shown and the anastomotic stomas were unobstructed. Conclusions It is feasible to evaluate the curative effects of cerebral internal and external vascular bypass graft by combining CTP images of cerebral perfusion after therapy with CTA images of cerebral internal and external bypass grafts.