Willis环形态对单侧颈内动脉重度狭窄/闭塞患者脑血流灌注的影响

Effect of Willis circle morphology on cerebral blood flow perfusion in patients with unilateral internal carotid artery severe stenosis or occlusion

目的探讨Willis环形态对单侧颈内动脉重度狭窄/闭塞患者脑血流灌注的影响。方法分析139例单侧颈内动脉重度狭窄/闭塞患者头颅CT血管造影(CTA)和CT灌注成像(CTPI)资料,将Willis环形态分为Ⅰ型(完整Willis环)、Ⅱ型(前交通动脉ACo A不开放,双侧后交通动脉PCo A开放)、Ⅲ型(ACo A开放,双侧PCo A不开放)和Ⅳ型(ACo A和双侧PCo A均不开放),对称性选取双侧额、顶、枕和颞叶皮层及丘脑作为感兴趣区进行灌注参数值测量,包括脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)和达峰时间(TTP),计算患侧/健侧脑区灌注参数值相对比(r CBF、r CBV、r MTT、r TTP)并进行组间比较。结果差异脑区灌注参数组间比较显示,Ⅱ型组额叶皮层r CBV值小于Ⅰ型和Ⅲ型组,Ⅱ型和Ⅳ型组顶叶皮层r CBV值小于Ⅰ型组;Ⅱ型和Ⅳ型组额叶皮层r MTT值和r TTP值高于Ⅰ型和Ⅲ型组,Ⅱ型、Ⅲ型和Ⅳ型组顶叶、颞叶皮层r MTT值和r TTP值高于Ⅰ型组,上述差异均有统计学意义(均P<0.05)。结论 Willis环形态对单侧颈内动脉重度狭窄/闭塞患者脑组织低灌注状态的代偿作用存在差异,并且ACo A的开放对额叶皮层的代偿作用显著。

Objective To investigate the effect of Willis circle morphology on cerebral blood flow perfusion in patients with unilateral internal carotid artery severe stenosis or occlusion.Methods The data of head CT angiography（CTA） and CT perfusion imaging（CTPI） of 139 patients with unilateral internal carotid artery severe stenosis or occlusion were analyzed.The patients were divided into four groups：type Ⅰ（complete Willis circle）,type Ⅱ[the anterior communicating artery（ACo A） is not opening,and the bilateral posterior communicating arteries（PCo A） are opening],type Ⅲ（ACo A is opening,and the bilateral PCo A are not）,and type Ⅳ（both the ACo A and the bilateral PCo A are not opening）.The bilateral frontal,parietal,occipital and temporal lobe cortex,and thalamus were selected as regions of interest,and the perfusion parameters were measured,including cerebral blood flow（CBF）,cerebral blood volume（CBV）,mean transit time（MTT） and time to peak（TTP）.The ipsilateral and contralateral cerebral perfusion parameters value ratios（r CBF,r CBV,r MTT,r TTP） were calculated and compared between groups.Results The r CBV value of frontal cortex was less in type Ⅱ group than in type Ⅰ group and type Ⅲ group（P〈 0.05）,the r CBV value of parietal cortex was less in type Ⅱ group and type Ⅳ group than in type Ⅰ group（P 〈0.05）,the r MTT and r TTP values of frontal cortex were higher in type Ⅱ group and type Ⅳgroup than in type Ⅰ group and type Ⅲ group（P〈 0.05）,and the r MTT and r TTP values of parietal and temporal cortex were higher in type Ⅱ group,type Ⅲ group and type Ⅳ group than in type Ⅰ group（P 〈0.05）.Conclusion The compensatory effect of Willis circle morphology on cerebral hypoperfusion in patients with severe stenosis/occlusion of unilateral internal carotid artery is different,and the compensatory effect of ACo A is notable on the frontal cortex.