目的 探讨三维伪连续动脉自旋标记(3D-pcASL)灌注成像在超急性与急性缺血性脑梗死鉴别及预后评估中的应用.方法 收集我院收治的24例超急性与36例急性缺血性脑梗死患者作为观察对象,选取梗死最大层面测量DWI异常高信号面积(SDWI)和3D-pc ASL序列脑血流(cerebral blood flow,CBF)异常灌注面积(SCBF),分析理论缺血半暗带(ischemic penum-bra,IP).选取梗死核心(infarct core,IC)、SCBF和SDWI不匹配区(MACD)、相应对侧为感兴趣区(region ofinterest,ROI),分析梗死侧-对侧相对CBF值(rCBF)、相对FA值(rFA)、相对DCavg值(rDCavg).结果 在IC/对侧中,超急性组患者的rFA、rDCavg值明显高于急性组,二者存在统计学差异(P＜0.05).MACD/MACD对侧中,超急性组患者的rCBF、rDCavg值明显低于急性组,rFA值明显高于急性组,二者存在统计学差异(P＜0.05).超急性脑梗死与MACD的rCBF、rDCavg水平成反比,与MACD的rFA和IC的rFA、rDCavg水平成正比.结论 可采用3D-pcASL获取CBF,并结合FA、DCavg值变化水平,进而鉴别诊断患者处于超急性还是急性缺血性脑梗死.

Objective:To investigate the clinical value of three-dimensional arterial spin marker imaging(3D-ASL) for evaluating collateral circulation compensatory status in patients with cerebral infarction.Methods:A total of 24 patients with cerebral infarction who were treated at Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang University of Chinese Medicine from September 2017 to January 2019 were examined by 1.5-T high-field MR scanner.The changes of cerebral blood flow(CBF) between the infarcted area and the contralateral normal area were compared when the labeled delay time(PLD)=1.5s and PLD=2.5s, and the patients were divided into the group with strong collateral circulation compensation and the group with weak collateral circulation compensation according to the difference in lesion area measured by 3D-ASL(PLD=1.5s and 2.5s). The changes of national institutes of health stroke scale(NIHSS) score and Bathel index at admission and 15 days after admission were compared.Results:3D-ASL measurement of PLD=1.5s showed that the CBF value in the infarcted area was (33.70±20.83)mL/(100g×min), which was significantly lower than that in the contralateral normal area(PLD=1.5s)[(49.93±13.13)mL/(100g×min)]( t=3.229, P<0.05). When PLD=2.5s, ASL measurement results showed that the CBF value in the infarcted area increased significantly[(58.26±23.50)mL/(100g×min) vs.(33.70±20.83)mL/(100g×min)]( t=3.831, P<0.05), and the CBF value in the contralateral normal area also increased significantly[(68.29±14.03)mL/(100g×min) vs.(49.93±13.13)mL/(100g×min)]( t=4.681, P<0.05). At this time, the CBF value in the infarcted area was still significantly lower than that in the contralateral normal area[(58.26±23.50)mL/(100g×min) vs.(68.29±14.03)mL/(100g×min)]( t=1.795, P<0.05). On the day of admission, the BI index of patients in the weak collateral circulation compensation group(12 cases) was significantly higher than that in the strong collateral circulation compensation group(12 cases)[(90.42±10.50) vs.(67.92±27.57)]( t=2.642, P<0.05), and the NIHSS score was significantly lower than that in the strong collateral circulation compensation group[(1.25±1.01) vs.(3.83±3.62)]( t=2.378, P<0.05). After 15 d of admission, there were no significant differences in BI index and NIHSS score between the two groups(all P>0.05). Conclusion:3D-ASL with different delay time can effectively and intuitively reflect collateral circulation compensation of patients with cerebral infarction, and it has very important reference value for the evaluation of patients' disease and the formulation of clinical treatment plan.