不同程度慢性单侧大脑中动脉狭窄的脑血流动力学及血管成像研究

The Cerebral Hemodynamic and Angiography Study of Different Degree of Unilateral Chronic Middle Cerebral Artery Stenosis

目的利用CT灌注(CTP)探讨不同程度慢性单侧大脑中动脉(MCA)狭窄患者脑血流动力学改变,并联合CT血管成像(CTA)评价MCA狭窄程度及颅内血管情况与脑血流灌注参数的关系。资料与方法 89例MCA狭窄患者根据其狭窄程度分为3组。分别计算各组中MCA供血区CTP的均值和狭窄侧/对侧比值,评价各组的脑血流动力学改变。利用CTA联合DSA评估MCA狭窄程度及颅内血管情况与灌注参数的相关性。结果 (1)大部分患者长期处于"良性灌注不良"状态,脑血流量(CBF)维持稳定,脑血容量(CBV)升高,最大峰值时间(TTP)延长。(2)TTP比值(rTTP)与MCA狭窄程度具有较强的等级相关性(r=0.713,P<0.01),CBV比值(rCBV)与狭窄程度有弱相关性(r=0.365,P<0.01)。(3)对于Willis环发育异常或狭窄患者,其rTTP明显延长,提示脑血流动力学损害严重。结论 CTP联合CTA能够全面了解MCA狭窄脑血流动力学损伤情况。

Objective The purpose of this study is to evaluate hemodynamics and angiographic condition in different degree of unilateral chronic middle cerebral artery （MCA） stenosis with CT perfusion（CTP）plus angrography. Materials and Methods Eighty-nine patients with MCA steno-occlusion were classified into 3 groups according to the severity of the stenosis. Mean values and ratio of CTP parameters were compared in affected hemispheres with those in contralateral hemispheres to respectively evaluate the cerebral hemodynamics and the relationship with the degree of stenosis. Furthermore,the circle of willis were also investigated. Results （1） Most pateints should be a chronic state of ‘benign hypoperfusion＂,at this state,cerebral blood flow （CBF） always kept at rest,cerebral blood volume （CBV） increased and had significant different when stenosis was more than 70%,time to peak （TTP） were significantly increased when stenosis was more than 50%. （2） TTP ratio correlated highly significantly with the degree of stenosis （r=0.713,P〈0.01）,CBV and CBF ratio showed weak and no significant correlation （CBV,r=0.365,P〈0.01;CBF,r=0.193,P〉0.05）.（3） In addition,those patients with abnormalities Willis or stenosis had marked increase in the TTP ratio,which aggravated the impairment of hemodynamics. Conclusion CTP plus angiography measurement provided sufficient evaluations of hemodynamic constitutions and angiographic findings in unilateral chronic MCA steno-occlusion patients.