Abstract: Objective To explore the feasibility of the cerebrovascular reserve assessment with gantry angled perfusion computed tomography(CT) and carbon dioxide(CO2) test in patients with posterior circulation hemodynamic impairment.Methods Perfusion CT with 5% CO2 and 95% oxygen(O2) was used to investigate 9 symptomic vertebral-basilar artery stenosis patients with posterior circulation hemodynamic impairment. CT gantry angle was selected from -13 degree to -23.5 degree (mean -14.7±1.7degree) for the purpose that base line paralleled to vertical line of the level. This protocol could avoid bone artifacts furthest.Results The cerebrovascular reserve of brainstem ranged from -19.83% to 53.36% and of cerebellum ranged from -20.58% to 45.50%.Conclusion It is safe and feasible to assess cerebrovascular reserve with gantry angled perfusion CT and CO2 test in patients with posterior circulation hemodynamic impairment.

Key words: Tomography; X-ray computed; CO2 Test; Posterior circulation; Cerebrovascular reserve

摘要： 目的 观察倾斜扫描架CT灌注扫描联合CO2激发实验技术测定症状性椎基底动脉狭窄患者后循环脑血流储备的可行性。方法 灌注CT采用10排的螺旋CT，扫描架倾斜角-13～-23.5度（平均-14.7±1.7度），使基线平行于蝶鞍鞍背平面以最大程度地减轻骨伪影对定量测定脑血流量的干扰。激发实验采用5％CO2和95％O2混和气体，应用具有单向通气功能的简易呼吸气囊对9例症状性椎基底动脉狭窄患者进行了脑血流储备测定。结果 脑干的脑血流储备在-19.83%～53.36%之间；小脑的脑血流储备在-20.58%～45.50%之间。倾斜扫描架CT灌注扫描联合CO2激发实验可以测定症状性椎基底动脉狭窄患者后循环脑血流储备。结论 倾斜扫描架CT灌注扫描联合CO2激发实验测定症状性椎基底动脉狭窄患者后循环脑血流储备安全可行，值得进一步研究。

关键词: 体层摄影术; X线计算机; CO2激发实验; 后循环; 脑血流储备