目的: 分别采用高分辨率磁共振成像(high-resolution magnetic resonance imaging，HR-MRI)和颅脑三维伪连续动脉自旋标记(3D pseudo-continuous arterial spin labeling，3D pcASL)分析单侧颈动脉中重度狭窄患者斑块特征与脑血流量(cerebral blood flow，CBF)的相关性。方法: 选择43例单侧颈动脉中重度狭窄患者，采用HR-MRI分别测量颈动脉狭窄程度、最大管壁厚度(maximum wall thickness，Max WT)、标准化管壁指数(normalized wall index，NWI)，进行斑块特征分析，记录有无斑块内出血(intraplaque hemorrhage，IPH)、富脂坏死核(lipid-rich necrotic nuc-leus，LRNC)、钙化和溃疡，以及钙化和LRNC分级。采用3D pcASL测量双侧大脑中动脉供血区内感兴趣区的CBF值。采用配对样本t检验比较患侧和对侧CBF值差异，采用Spearman相关分析比较患侧颈动脉狭窄程度、Max WT、NWI与CBF值的相关性，采用Mann-Whitney U检验比较斑块成分中有无IPH、溃疡时CBF值的差异，采用Kruskal-Wallis检验比较不同级别钙化、LRNC时CBF值差异。结果: 患侧颈动脉平均狭窄程度为77.30%±11.79%。患侧和对侧平均CBF值分别为(46.77±11.65) mL/(100 g·min)和(49.92±9.95) mL/(100 g·min)，差异有统计学意义(t=-2.474，P=0.017)。患侧颈动脉斑块平均Max WT为(6.40±1.87) mm，平均NWI为62.91%±8.87%。患侧颈动脉狭窄程度、Max WT、NWI与CBF值未见明显相关(P>0.05)。斑块成分分析显示，患侧斑块内有无钙化及钙化程度不同时，CBF值有差异(P=0.030)，有无IPH、溃疡及LRNC时的患侧CBF值差异无统计学意义。结论: 单侧颈动脉中重度狭窄患者中，斑块内钙化可能影响脑血流灌注，当无钙化存在时，需要特别关注斑块成分。

Objective: To investigate the correlations between carotid plaque characteristics and cerebral blood flow (CBF) in patients with unilateral moderate to severe carotid stenosis using high-resolution magnetic resonance imaging (HR-MRI) and 3D pseudo-continuous arterial spin labeling (3D pcASL). Methods: A total of 43 patients with unilateral moderate to severe carotid stenosis were recruited. The degree of carotid stenosis, maximum wall thickness (Max WT) and normalized wall index (NWI) were measured using HR-MRI. The plaque characteristics were analyzed. Presence or absence of plaque components including intraplaque hemorrhage (IPH), lipid-rich necrotic nucleus (LRNC), calcification and ulcer were identified, and the grades of calcification and LRNC were recorded. CBF values within the region of interest representing the bilateral middle cerebral artery distribution were acquired using 3D pcASL. Paired sample t test was used to compare the differences of CBF values between the index side and the contralateral side. Spearman correlation analysis was conducted to evaluate the correlations of CBF values with the degree of carotid stenosis, Max WT and NWI. The differences of CBF values between the patients with or without IPH and ulcer were compared using Mann-Whitney U test. Different levels of calcification and LRNC were compared by Kruskal-Wallis test, respectively. Results: The ave-rage degree of carotid stenosis at the index side was 77.30%±11.79%. The mean CBF value of the index side was (46.77±11.65) mL/(100 g·min), and that of the contralateral side was (49.92±9.95) mL/(100 g·min), and the difference was statistically significant (t=-2.474, P=0.017). The mean Max WT and NWI of the carotid plaques at the index side was (6.40±1.87) mm and 62.91%±8.87%, respectively. There were no significant correlations of CBF values with the degrees of stenosis, Max WT and NMI (P>0.05). Plaque composition analysis showed that the CBF values of the index side were different when there was calcification or not and the degrees of calcification were different (P=0.030), but there were no differences between the CBF values on the index sides with or without IPH, ulcer and LRNC. Conclusion: In patients with unilateral moderate to severe carotid stenosis, calcification might affect CBF perfusion. When there is no calcification, the plaque components need attention.