磁共振全脑容积动脉自旋标记成像评价单侧颈动脉狭窄患者脑血流动力学的初步研究

目的探讨磁共振全脑容积灌注3D动脉自旋标记（3DASL）成像在单侧颈动脉狭窄或闭塞中的应用价值。方法对连续36例单侧颈动脉狭窄患者（经数字减影血管造影（DSA）验证）行颈部磁共振血管成像（MRA）与头部MR3DASL检查。检验颈部MRA与DSA在狭窄程度上诊断的一致性。以DSA诊断的狭窄程度为标准，将36例患者分成轻、中、重3组，对3DASL所测得的患侧，健侧脑血流量（CBF）比率进行方差分析。以临床症状为标准，将重度狭窄的患者分为有症状组和无症状组，分析2组患侧，踺侧CBF比率的统计学意义。结果颈部MRA与DSA在动脉血管狭窄程度上的诊断，经Kappa行一致性检验，有很强的一致性（Kappa〉0．75，P〈0．05）。轻、中度狭窄组间患侧楗侧CBF比率差别无统计学意义（P〉O．05）；重度狭窄组与轻、中度狭窄组患侧健侧CBF比率差别均有统计学意义（P〈0．01）。重度狭窄患者的有症状组与无症状组患侧，睦侧CBF比率差别有统计学意义（P〈0．01）。结论3DASL技术作为一种安全、无创和可重复的检查方式，配合颈部MRA，对评价单侧颈动脉狭窄患者脑血流动力学状况在临床诊治方面有重要意义。

Preliminary study of cerebral hemodynamics evaluation by MR 3D arterial spin labeling for patients with unilateral carotid stenosis

Objective To investigate the application value of 3D arterial spin labeling （ASL） perfusion imaging for patients with unilateral carotid stenosis or occlusion. Methods Cervical MRA and cerebral 3D ASL were performed on 36 consecutive patients with unilateral carotid stenosis diagnosed by digital subtraction angiography （DSA）. The consistency of degree of stenosis between cervical MRA and DSA was analyzed. 36 patients were divided into mild, moderate and severe groups by degree of stenosis, which was based on the DSA result. Variance analysis of cerebral blood flow （CBF） unilateral and contralateral changes were performed on three different groups. Patients with severe stenosis, diagnosed by DSA, were divided into symptomatic group and asymptomatic group. Analysis was carried out on unilateral and contralateral change differences between symptomatic group and asymptomatic group. Results There was no statistical significance between MRA and DSA in the cervical artery stenosis degree （kappa〉 0.75, P〈0.05）. There was no statistical difference in CBF unilateral and contralateral changes between mild group and moderate group （P〉0.01）. There was statistical difference in CBF unilateral and contralateral changes between severe group and other two groups （P〈0.01）. There was statistical difference in CBF unilateral and contralateral changes between symptomatic group and asymptomatic group （P〈0.01）. Conclusion 3D ASL, as a safe, non-invasive, repeatable method, are meaningful for cerebral hemodynamics evaluation in patients with unilateral carotid stenosis