TOF-MRA、3D-ASL联合区域选择ASL对烟雾病血管重建术后的血流评估

Evaluating blood flow status after revascularization in patients with moyamoya disease by using TOF-MRA,3D-ASL and territory ASL

目的探讨时间飞跃法磁共振血管成像(time-of-flight MR angiography,TOFMRA)、三维动脉自旋标记(three-dimensional arterial spin labeling,3D-ASL)联合区域选择ASL(territory arterial spin labeling,T-ASL)监测烟雾病血管重建术后血流状态的应用价值。材料与方法回顾性分析2017年3月至2019年3月18例进行血管重建术的烟雾病患者的19个大脑半球。分别于术前、术后进行TOF-MRA、3D-ASL及T-ASL检查,术后随访时间为3.5~14.5个月。运用TOF-MRA观察术后颅内-外沟通血管状态;在依据Alberta卒中操作早期CT评分(Alberta Stroke Programme Early Computed Tomography Score,ASPECTS)分区基础上,运用3D-ASL对比术前术后脑组织脑血流量(cerebral blood flow,CBF)及相对脑血流量(relative cerebral blood flow,rCBF)值,评估脑组织灌注情况。运用T-ASL计算同侧颈外动脉(external carotid artery,ECA)供血脑组织的体积及血流覆盖深部脑组织的范围。结果TOF-MRA显示术后颅内-外沟通血管包括单一的、粗大的搭桥血管(73.7%,14/19)和簇状的、较细的新生侧支血管(57.9%,10/19)。手术前后ASL-CBF分别为(41.4±19.3)ml/100 g·min、(48.9±15.1)ml/100 g·min,rCBF分别为0.88±0.34、1.08±0.26,差异均有统计学意义(P<0.01)。血流重建区(revascularization area,RA)体积范围4.85~370.91 ml,中位数为109.72 ml。RA对深部脑组织的灌注显示,15.8%(3/19)的RA区域覆盖了基底节、丘脑等深部脑组织,63.2%(12/19)的RA区域覆盖了同侧大脑深部皮层,21.1%(4/19)的RA区覆盖了对侧大脑深部皮层。RA体积大于100 ml的10例大脑半球9例同时显示搭桥动脉及簇状新生侧支动脉,RA体积小于100 ml的9例患者,仅显示搭桥动脉或仅显示稀疏的新生侧支动脉。结论联合应用TOF-MRA、3D-ASL、T-ASL可以显示烟雾病血管重建术后颅内-外血管情况、监测脑血流量变化、客观显示RA体积及覆盖范围,在烟雾病血管重建术后血流状态评价方面具有重要的应用价值。

Objective:To investigate the value of time-of-flight MR angiography(TOF-MRA),three-dimensional arterial spin labeling(3D-ASL)and territory ASL(T-ASL)in monitoring blood flow status of patients with moyamoya disease after revascularization.Materials and Methods:This retrospective study was conducted in 19 hemispheres of 18 patients with moyamoya disease who underwent revascularization operation in March 2017 to March 2019.TOF-MRA,3D-ASL and T-ASL were performed pre-and postoperatively,and the postoperative follow-up time was 3.5—14.5 months.TOF-MRA scan was used to observe the postoperative intracranial-external communication artery.Base on Alberta Stroke Programme Early Computed Tomography Score(ASPECT)system,3D-ASL was used to compare pre-and postoperative cerebral blood flow(CBF)and relative cerebral blood flow(rCBF).T-ASL was used to calculate the volume of reconstruction area(RA)and the perfusion of deep brain structures by the external carotid artery(ECA)on the operated side.Results:TOF-MRA showed that postoperative intracranial-external communication arteries included single,thick bypass vessels(73.7%,14/19)and clustered,thin new collateral vessels(57.9%,10/19).Before and after surgery,ASLCBF was(41.4±19.3)ml/100 g·min and(48.9±15.1)ml/100 g·min),and rCBF was 0.88±0.34 and 1.08±0.26 respectively,with statistically significant differences(P<0.01).RA volume ranges from 4.85 to 370.91 ml,with a median of 109.72 ml.Perfusion of deep brain structures by ECA showed that 15.8%(3/19)of RA region covered deep brain structures such as ipsilateral basal ganglia and thalamus,63.2%(12/19)of RA region covered ipsilateral deep cerebral cortex,and 21.1%(4/19)of RA region covered contralateral deep cerebral cortex.Nine of the 10 patients with RA volume greater than 100 ml showed both bypass arteries and clustered collateral arteries,while 9 patients with RA volume less than 100 ml showed only bypass arteries or only sparse collateral arteries.Conclusions:The combined application of TOF-MRA,3D-ASL and T-ASL can monitor the intracranial-external communication artery condition,identify the CBF changes,calculate RA volume and observe coverage area objectively after revascularization of moyamoya disease,and it is valuable to monitoring blood flow status after revascularization in patients with moyamoya disease.