三维伪连续式动脉自旋标记技术评估大脑中动脉狭窄后侧支循环的初步研究

Three-dimension pseudo-continuous arterial spin labeling to evaluate collateral circulation in patients with cerebral artery stenosis

目的 :探讨多参数三维伪连续式动脉自旋标记(3D-pcASL)技术评估单侧大脑中动脉狭窄后侧支循环及代偿能力的临床价值。方法:收集CTA或MRA检查提示单侧大脑中动脉狭窄(狭窄程度≥50%)患者46例,按临床症状分为有症状组(31例)及无症状组(15例)。2组均行2个标记后延迟(PLD)时间(1.5、2.5 s)3D-pcASL检查,获得2个延迟时相的脑血流量(CBF)伪彩灌注图;将2个PLD的CBF图像相减并对所得残影面积行定量分析。结果:PLD=1.5 s时,2组血管狭窄侧脑区CBF值均较健侧相应脑区降低(均P<0.01)。当PLD=2.5 s时,2组血管狭窄侧脑区CBF值均较健侧相应脑区降低(均P<0.01),且血管狭窄侧CBF值较PLD=1.5 s不同程度升高。无症状组2个PLD灌注剪影图残影面积大于有症状组,差异有统计学意义(P> 0.05)。结论:多参数3D-pcASL可用于定量评估脑血管狭窄后脑组织缺血情况,以及侧支循环形成和代偿能力。

Objective:To explore the application of multi-parameter three-dimensional pseudo-continuous arterial spin labeling(3D-pcASL)in evaluating collateral circulation and compensatory ability in patients with unilateral middle cerebral artery(MCA)stenosis.Methods:A total of 46 patients with unilateral MCA stenosis(≥50%)were collected that verified by CTA or MRA.According to clinical symptoms,all patients were divided into the symptomatic group(31 cases)and asymptomatic group(15 cases).All patients were performed 3D-pcASL(including PLD of 1.5 s and 2.5 s)in 3.0 T MRI scanner that obtained the whole brain cerebral blood flow(CBF)perfusion maps.CBF subtraction images and the afteriamge area between two PLDs were compared in the symptomatic and asymptomatic group,respectively.Results:At PLD of 1.5 s,CBF values of the MCA stenosis side brain of the two groups were lower than those in the healthy side brain,and the same change happened at PLD of 2.5 s.And the CBF values of the stenosis side increased varying degrees at PLD of 2.5 s.The afteriamge area of the asymptomatic group was bigger than that of the symptomatic group at the two PLDs.Conclusion:Different PLD of 3D-ASL can be used to evaluate collateral circulation and compensatory ability quantitatively in patients with cerebral artery stenosis.