单侧颈动脉狭窄致继发性慢性脑缺血的CT灌注研究

The Characteristics of CT Perfusion in Chronic Cerebral Ischemia Caused by Unilateral Carotid Artery Stenosis

目的探讨单侧颈动脉狭窄所致慢性脑缺血(CCI)的CT灌注成像(CTP)特点及与颈动脉狭窄程度的相关性。方法回顾性分析临床诊断慢性脑供血不足且经头颈CTA证实仅单侧颈动脉狭窄36例患者的CTP表现,分别测量额叶、基底节区、颞叶健侧和患侧的相对血容量(r CBV)、相对血流量(r CBF)、平均通过时间(MTT)及达峰时间(TTP),统计分析各参数患侧及健侧的统计学差异;按颈动脉狭窄程度进行分组,并统计分析组内各参数的统计学差异,分析CCI与颈动脉狭窄程度的相关性。结果 36例中左侧颈动脉狭窄17例,右侧颈动脉狭窄19例;轻度狭窄11例,中度狭窄17例,重度狭窄8例;轻、中度狭窄组各灌注参数均无统计学意义(P>0.05),重度狭窄组r CBV、r CBF、MTT、TTP均有明显统计学差异(P<0.05)。结论 CTP能反映单侧颈动脉狭窄所致CCI的血流动力学变化,为临床诊断及治疗提供依据。CCI患者脑组织血流动力学变化与颈动脉狭窄程度具有一定的相关性。

Objective To investigate the relationship between the characteristics of CT perfusion in chronic cerebral ischemia caused by unilateral carotid artery stenosis and the degree of carotid stenosis. Methods To retrospectively analyze the CT perfusion images of unilateral carotid artery stenosis confirmed by CTA in 36 patients who were proposed to diagnose chronic cerebral ischemia. Relative cerebral blood volume（ r CBV）,relative cerebral blood flow（ r CBF）,mean transit time（ MTT） and time to peak（ TTP） in both sides of frontal lobe,basal ganglia region and temporal were measured respectively,and the differences between the two sides were statistically analyzed. Then,the 36 cases were grouped according to the degree of carotid stenosis,and the correlation between the groups were analyzed. Results Of 36 cases,left carotid arterial stenosis occurred in 17 patients,and right in 19; the mild,moderate and severe stenosis cases were 11,17 and 8 respectively; the parameters of perfusion had no statistical significance difference（ P 〉 0. 05） in mild and moderate stenosis group; and in severe stenosis group,r CBV,r CBF,MTT,TTP had significant statistical significant difference（ P 〈0. 05）. Conclusion CT perfusion imaging could reflect the hemodynamic changes of chronic cerebral ischemia caused by unilateral carotid artery stenosis,which would provide the basis for clinical diagnosis and treatment. Hemodynamic changes in patients with chronic cerebral ischemia had a certain relevance with the degree of the carotid artery stenosis.