CT灌注成像联合CT血管造影评价颈内动脉或大脑中动脉狭窄患者脑血流灌注及Willis环结构对灌注分布的影响

CT perfusion imaging combined with CT angiography in assessment of cerebral perfusion and impact of Willis circle structure in patients with internal carotid artery or middle cerebral artery stenosis

目的探讨脑CT灌注(CTP)成像联合CTA检查颈内动脉或大脑中动脉狭窄患者脑血流灌注情况及Willis环结构对脑血流灌注分布影响的价值。方法对经颅多普勒(TCD)诊为单侧颈动脉狭窄的42例患者行CTP联合CTA检查,观察血管狭窄部位、程度、Willis环形态及脑血流灌注情况。结果经CTP联合CTA检查,29例为颈内动脉狭窄,13例为大脑中动脉狭窄;轻度狭窄11例,中度狭窄13例,重度狭窄14例,闭塞4例。狭窄侧与对侧血管相比,轻度狭窄患者各灌注参数差异均无统计学意义(P均>0.05);中度狭窄患者狭窄侧MTT、TTP高于对侧(P均<0.05);重度狭窄或闭塞患者狭窄侧CBF低于对侧,CBV、MTT、TTP高于对侧(P均<0.05)。42例中21例存在灌注异常,颈内动脉与大脑中动脉狭窄患者间异常灌注区分型差异有统计学意义(P<0.05)。结论CTP联合CTA检查可较好地评价颈内动脉或大脑中动脉狭窄患者脑血流动力学及Willis环血管形态。

Objective To assess the cerebral perfusion and the impact of Willis circle structure in patients with internal carotid artery（ICA） or middle cerebral artery（MCA） stenosis using CT perfusion（CTP） imaging combined with CTA.Methods Totally 42 patients with unilateral carotid artery stenosis screened by transcranial doppler（TCD） underwent combined CTP and CTA examination.The site and extent of stenosis,structure of Willis circle and blood perfusion were studied.Results Abnormal signs were observed in all patients,including ICA stenosis in 29 cases and MCA stenosis in 13 cases.Mild,moderate and severe stenosis was found in 11,13 and 14 cases,respectively,and occlusion was found in 4 cases.There was no significant difference of perfusion parameters between bilateral vessels in mild stenosis cases（all P〉0.05）.MTT and TTP of stenosis side vessel were higher than those of contralateral side in moderate stenosis cases（all P〈0.05）.In severe stenosis or obstruction cases,CBV,MTT and TTP of stenosis side vessel were higher than those of contralateral side,while CBF of stenosis side vessel was lower than contralateral side（all P〈0.05）.Abnormal cerebral perfusion was observed in 21 patients.Significant statistical difference of abnormal cerebral perfusion classification was found between ICA and MCA stenosis patients.Conclusion CTP combined with CTA is an effective method to assess t cerebral perfusion and the structure of Willis circle in patients with ICA or MCA stenosis