目的： 探讨动脉自旋标记（anerial spin labeling,ASL）磁共振灌注技术结合磁共振血管成像（magnetic reso-nance angiography,MRA）在预测后循环脑梗死（posterior circulation ischemia,PCI）患者病情进展中的作用。方法： 根据入院72 h后美国国立卫生研究院卒中量表（National Institute of Health stroke scale,NIHSS）评分是否增加≥3分（作为病情进展标准）,将57例PCI患者分为进展组和对照组,对患者行脑部MRI的T1加权、T2加权、FLARE、MRA、弥散加权成像（diffusion weighted imaging,DWI）、ASL序列扫描,并进行后循环急性卒中预后早期CT量表（posterior circulation Alberta Stroke Program Early CT Score,pc-ASPECTS）评分,计算相对脑血流（relative cerebral blood flow,rCBF）值,记录颅内大动脉狭窄程度。比较进展组与对照组间的ASL参数及其他指标差异,并对有差异的数据进行多因素Logistic回归分析。结果： 对照组的rCBF值明显高于进展组（1.25±0.37比0.69±0.19,P<0.05）,其pc-ASPECT评分也显著高于进展组[（8.21±0.74）分比（7.69±0.93）分,P<0.05],但rCBF值与pc-ASPECTS间无相关性。进展组患者的大动脉狭窄发现率（根据MRA结果）高于对照组（82.76%比35.71% P<0.05）,且rCBF值与大动脉狭窄率相关,但10例大动脉狭窄者的rCBF值并未降低。多因素Logistic回归分析显示,只有高rCBF值（OR=3.703,95%CI为1.971~6.956）是PCI病情进展的保护因素（P<0.05）,受试者工作特征曲线显示,rCBF值≥1.014的PCI患者的预后较好,即72 h内疾病无进展。结论： 高rCBF值是PCI病情进展的保护因素。对于PCI患者,pc-ASPECT评分、MRA大动脉狭窄率都可能无法全面反映疾病的短期进展,故行MRI、MRA检查并结合ASL检测rCBF值,可更好地预测PCI的早期病情进展。

Objective: To investigate the application of arterial spin labeling magnetic resonance perfusion imaging (MRI-ASL) combined with magnetic resonance angiography (MRA) for predicting the progress of PCI stroke. Methods: According to whether there was an increase of ≥3 scores of National Institute of Health Stroke Scale(NIHSS) 72 hours after admission, 57 patients with acute posterior circulation ischemic stroke were divided into progressive group (n=29) and control group (n=28). All patients were examined with standard magnetic resonance scans (T1WI、T2WI、T2-FLAIR), MRA, diffusion weighted imaging(DWI) and MRI-ASL. The patients were also evaluated with the posterior circulation Alberta Stroke Program Early CT Score(pc-ASPECTS). Relative cerebral blood flow（rCBF） and degree of main arterial stenosis were recorded. The differences of these parameters between progressive group and control group were measured, and multivariate logistic regression analysis was performed on parameters with significant differences. Results: The rCBF [（1.25±0.37） vs. (0.69±0.19), P<0.05] and pc-ASPECTS [（8.21±0.74） vs. (7.69±0.93), P<0.05] in control group were significantly higher than those in progressive group, however, there was no correlation between rCBF and pc-ASPECTS. The main arterial stenosis rate in progressive group were significantly higher than that in control group (82.76% vs. 35.71%, P<0.05), and rCBF was correlated with main arterial stenosis rate. However, the rCBF of 10 cases with main arterial stenosis was not decreased. Multivariate logistic regression analysis revealed that only rCBF （OR=3.703, 95%CI 1.971-6.956） was the protective factor of progression of PCI stroke. ROC curve analysis indicated that rCBF（≥1.014） predicted good prognosis. Conclusions: High rCBF is a protective factor of progreesion of PCI. For PCI patients, pc-ASPECT score, MRA detected main arterial stenosis rate could not comprehensively reflect the short term progression of the disease; MRI, MRA combined with MRI-ASL detecting the rCBE could more effectively predicting the progression of early stage PCT.