目的：采用经颅多普勒（TCD）、CT灌注成像（CTP）分析颈内动脉（ICA）不同程度狭窄或闭塞患者脑血流动力学改变，探讨ICA狭窄或闭塞患者临床表现、脑灌注与侧支循环之间的相互关系。方法48例患者行TCD、双能量CT血管成像（CTA）及CTP检查。CTA诊断单侧ICA病变38例，双侧ICA病变8例，未见异常2例。根据临床表现分为症状组与无症状组，分析各组患者TCD及CTP血流动力学参数等特点。结果TCD示单侧ICA轻、中度狭窄患者MCA的Vm及PI与对照组比较差异无统计学意义；单侧ICA重度狭窄或闭塞患者无症状组MCA的Vm及PI低于对照组，但MCA的Vm与对照组比较差异无统计学意义，而PI与对照组比较差异有统计学意义（P＜0.05）；单侧ICA重度狭窄或闭塞患者症状组MCA的Vm及PI较无症状组及对照组均明显减低（P＜0.05）。临床症状与狭窄程度及颅内侧支循环有关，单侧ICA重度狭窄或闭塞无症状组较症状组侧支循环开放数量明显增多。CTP结果显示单侧ICA轻度狭窄患者、中度狭窄患者无症状组及症状组基底节区、颞叶及额叶的脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）、达峰时间（TTP）与对照组比较差异无统计学意义。单侧ICA重度狭窄或闭塞患者无症状组颞叶CBF、CBV、MTT与对照组比较差异无统计学意义，但TTP较对照组延长（P＜0.05）。单侧ICA重度狭窄或闭塞患者症状组基底节区、颞叶CBF、MTT及TTP与对照组比较差异有统计学意义（P＜0.05），而CBV比较差异无统计学意义。双侧ICA重度狭窄或闭塞患者易出现双侧脑灌注下降。结论ICA重度狭窄或闭塞患者临床表现、脑灌注改变与侧支循环开放类型密切相关，良好的侧支循环能够维持脑灌注在正常范围。%Objective TCD combined with CTP to evaluate cerebral hemodynamics in patients with various degrees of ICA stenosis or occlusion, so as to explore the correlation of clinical manifestation, cerebral perfusion,and collateral circulation. Methods 48 patients underwent TCD, dual energy CTA and CTP examination. CTA showed 38 cases with unilateral ICA stenosis or occlusion, 8 cases with bilateral ICA stenosis or occlusion, and 2 patients no abnormal. They were divided into symptomatic group and asymptomatic group according to their clinical manifestations. The characteristics of cerebral hemodynamics of the patients on TCD and CTP were analyzed. Results Vm and PI of MCA distal to the ICA with mild or moderate stenosis on TCD showed no significant difference as compared with the control group. Both Vm and PI of MCA in the asymptomatic group with ICA severe stenosis or occlusion decreased, but only MCA PI decreased significantly as compared with the control group. Both Vm and PI of MCA in the symptomatic group with ICA severe stenosis or occlusion decreased significantly as compared with the control group and with the asymptomatic group. Clinical manifestations were correlated with degrees of stenosis and cerebral collateral circulation. As for the patients with unilateral ICA severe stenosis or occlusion, there were more circulation flow patterns in the asymptomatic group than in the symptomatic group. Compared with the control group, the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transmit time (MTT), the time to peak (TTP) at the basal ganglia, temporal lobe and frontal lobe on CTP in the patients with unilateral ICA mild or moderate stenosis (both symptomatic and asymptomatic group) showed no significant difference. Compared with the control group, the CBF, CBV, and MTT at the temporal lobe of the asymptomatic group with unilateral ICA severe stenosis or occlusion showed no significant difference, but the TTP delayed (P<0.05). Compared with the control group, the CBF, MTT, and TTP at the basal ganglia and temporal lobe of the symptomatic patients with unilateral ICA severe stenosis or occlusion showed significant difference (P<0.05), but the CBV showed no significant difference (P>0.05). Patients with bilateral ICA severe stenosis or occlusion often showed whole brain poor perfusion. Conclusion Clinical manifestations, and cerebral perfusion of patients with ICA severe stenosis or occlusion correlated closely with collateral circulation. Effective collateral circulation could maintain normal cerebral perfusion.
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