症状性单侧颈内动脉颅内段严重狭窄或闭塞全脑CT灌注成像表现模式

目的:研究症状性单侧颈内动脉(ICA)严重狭窄或闭塞的320排CT全脑灌注成像(CTPI)表现及血流动力学模式。资料与方法:回顾分析23例症状性单侧ICA严重狭窄(>70%)或闭塞的患者的全脑CTPI资料,分别重建4D-CTA及CTPI参数图(脑血容量(CBV)、脑血流量(CBF)、平均通过时间(MTT)、达峰时间(TTP)及延迟(Delay)图),分别记录ICA狭窄程度、患者临床症状、有无梗死及梗死部位、CTPI参数图特点及绝对值,并对病灶侧及对侧脑区灌注参数值进行比较。结果:单侧ICA闭塞15例,严重狭窄8例。大脑中动脉(MCA)和/或大脑前动脉(ACA)分布区脑梗死13例,内侧分水岭区梗死6例,基底节区腔隙性脑梗死2例,无梗死2例。CTPI血流动力学模式有:①CBV/CBF基本正常,MTT/TTP/Delay延长(4例);②CBV基本正常,CBF轻度下降,MTT/TTP/Delay延长(3例);③CBV/CBF明显减低,MTT局灶缩短并周围MTT/TTP/Delay延长(16例)。统计学分析显示:病灶同侧CBV、CBF、TTP、Delay与对侧比较差异有统计学意义(P<0.05);病灶同侧MTT与对侧比较差异无统计学意义(P=0.66)。结论:320排CT全脑容积CTA/CTPI能一次显示颅内段ICA的狭窄程度并能全面反映脑血流动力学变化,为临床治疗提供重要信息。

The whole brain CT perfusion imaging findings of symptomatic severe stenosis or occlusion of intracranial internal carotid artery

Objective： To study the hemodynamic patterns demonstrated in whole brain CT perfusion images（CTPI） in patients with symptomatic severe stenosis or occlusion of intracranial internal carotid artery（ICA）.Materials and Methods： The CTPI data of 23 patients with symptomatic severe stenosis（70%） or occlusion of ICA were analyzed retrospectively.The 4 dimensional CT angiography（4D-CTA） and the parameter maps of CTPI including cerebral blood volume（CBV）,cerebral blood flow（CBF）,mean transit time（MTT）,time to peak（TTP） and delay maps were generated in the off-line workstation by using specific software.The stenosis degree of ICA,clinical symptoms,location of infarction and features of CTPI and the values of parameter maps were recorded.Paired t-test was used to compare the values of ipsilateral with contralateral normal areas in CTP maps.Results： Fifteen patients had occlusion and 8 patients had severe stenosis of ICA.Thirteen cases had infarction in middle cerebral artery（MCA） or anterior cerebral artery（ACA） areas,6 cases had watershed infarction,2 cases had lacunar infarction and 2 cases had no infarction.The patterns of CTPI abnormalities included the following： ①Normal or slightly increased CBV/CBF and increased MTT/TTP/Delay time（4 csaes）.②Normal CBV,slightly decreased in CBF and decreased in MTT/TTP/Delay time（3 cases）.③Decreased obviously in CBV/CBF,decreased in regional MTT associated with prolong MTT/ TTP/Delay time（16 cases）.CBV,CBF,TTP and Delay values of ipsilateral side brain areas had significant difference when compared with those of contralateral brain areas（P〈0.05）.Conclusions： 320-row CT is a reliable technique in showing intracranial ICA stenosis and perfusion abnormalities.