CT灌注成像评估单侧大脑中动脉狭窄患者脑血流动力学和血管成形术及支架置入术疗效

摘要

目的 CT灌注(CTP)成像评价单侧大脑中动脉(MCA)狭窄患者脑血流动力学变化和血管成形术及支架置入术(PTAS)效果.方法 选取单侧MCA狭窄患者40例,根据CTA测量狭窄程度分为中度狭窄(50％～69％)组14例和重度狭窄(70％～99％)组26例,另根据药物疗效将重度狭窄组分为有效亚组16例和无效亚组10例.利用CTP评估狭窄侧与对侧的绝对灌注值,包括脑血流量(CBF)、脑血容量(CBV)和达峰时间(TTP),及相对灌注值(rCBF、rCBV、rTTP),评价支架治疗术前及术后脑血流动力学情况.结果 中度狭窄组狭窄侧与对侧比较,仅TTP差异有统计学意义(t=20.55,P＜0.01),重度狭窄组CBV和TTP的差异均有统计学意义(CBV:t=3.83,P＜0.001;TTP..t=8.89,P＜0.001).治疗无效亚组rTTP较有效亚组显著延长(t=-2.18,P=0.04).无效亚组接受PTAS后,rTTP较术前明显缩短(t=5.94,P＜0.001).结论 CTP能有效评估MCA狭窄患者脑血流动力学的变化,筛选介入治疗患者,TTP能敏感反映术后血流动力学改变.%Objective To assess the changes of cerebral hemodynamics and the effect of percutaneous transluminal angioplasty and stenting (PTAS) in patients with unilateral middle cerebral artery (MCA) stenosis by CT perfusion (CTP).Methods Forty patients with unilateral MCA stenosis were tested by CTA and divided into moderate stenosis (50％-69％) group (n=14) and severe stenosis (70％-99％) group (n=26) according to the degree of stenosis.Then,the severe stenosis group was divided into efficient subgroup (n=16) and inefficient subgroup (n=10) according to the drug efficacy.The mean values,i.e.cerebral blood flow (CBF),cerebral blood volume (CBV),time to peak (TTP) and specific values (rCBF,rCBV,rTTP) of the stenotic side and the opposite side were assessed by CTP,and the preoperative and postoperative cerebral hemodynamics conditions was evaluated.Results There was statistical difference in TTP (t =20.55,P＜0.01) between the stenotic side and the contralateral side in moderate stenosis group.However,there were statistical differences in CBV and TTP between the stenotic side and the contralateral side in severe stenosis group (CBV:t=3.83,P＜0.001,TTP:t=8.89,P＜0.001).The rTTP was significantly longer in inefficient subgroup than that in efficient subgroup (t=-2.18,P =0.04).After the PTAS in inefficient subgroup,the rTTP was significantly shorter than that before treatment (t=5.94,P＜0.001).Conclusion CTP can assess the hemodynamics impaired effectively in patients with unilateral MCA stenosis,and select the patients for interventional therapy.TTP can reflect the changes of postoperative hemodynamics sensitively.