目的：通过多排螺旋计算机断层扫描血管成像技术 （multi-detector computed tomography angiography，MDCTA）评价无症状性与症状性颈动脉狭窄患者斑块的成分和体积的差异。方法： 回顾性分析2011年7月至2015年12月在北京大学中日友好临床医学院连续行血管造影确诊的颈内动脉狭窄≥70%患者的临床资料。症状性患者定义为6个月内出现一过性黑朦、短暂性脑缺血发作及非致残性脑卒中者，否则定义为无症状性患者。共有78例患者符合条件，其中无症状性患者35例（44.9%），症状性患者43例（55.1%）。所有患者造影前一个月内行MDCTA检查。通过MDCTA利用后处理工作站斑块分析软件并根据不同的HU值将颈动脉斑块分为脂质斑块（富含脂质坏死核心，≤60 HU）、纤维斑块（60~130 HU）和钙化斑块（≥130 HU），计算斑块的总体积，各种斑块的体积及所占的比例，并比较两组之间的差异。结果：无症状性患者的钙化斑块比例明显高于症状性患者（t=2.760,P=0.007），而脂质斑块比例低于症状性患者（Z=-2.009, P=0.044），差异有统计学意义。多因素分析表明钙化斑块比例与无症状性颈动脉狭窄呈正相关(OR=0.949，95% CI：0.915~0.985，P=0.005)，脂质斑块比例与无症状性颈动脉狭窄呈负相关(OR=1.068，95%CI：1.021~1.117，P=0.004)。对于症状性患者，当脂质斑块比例大于30.3%时，其特异度为94.3%，而敏感度仅为37.2%。两组斑块体积及纤维斑块比例差异无统计学意义。 结论： 与症状性颈动脉狭窄斑块相比，无症状斑块钙化比例增加、脂质比例减少，脂质斑块比例大于30.3%在临床上可以作为预测症状性斑块一个有用的截点，对于颈动脉狭窄患者，可以应用MDCTA斑块分析进行风险评估。

Objective： To evaluate the differences of plaquecomposition and volume between symptomatic and asymptomatic patients with carotid artery stenosis by multi-detector computed tomography angiography (MDCTA). Methods: The consecutive patients with internal carotid artery stenosis≥70% diagnosed by digital subtraction angiography (DSA) were retrospectively analyzed from July 2011 to December 2015 in Peking University China-Japan Friendship School of Clinical Medicine. The symptomatic patients were defined as those who experienced nondisabling ischemic stroke or transient cerebralis chemic symptoms, including hemispheric events oramaurosis fugaxin the last 6 months. Otherwise, the patients were considered as a symptomatic. A total of 78 patients were enrolled in the study. Of these patients, there were 35 asymptomatic patients (44.9%) and 43 symptomatic patients (55.1%). All the patients received MDCTA before DSA. According to the plaque analysis of post processing work station, carotid plaques were divided into lipid-rich necrotic coreplaques (HU≤60), fibrous plaques (60 to 130 HU) and calcified plaques (HU≥130) through the different value sthreshold of HU. The plaque volume and proportion were all calculated. The differences between the two groups were compared by statistical methods. Results: The proportion of calcified plaques in asymptomatic patients was significantly higher than in symptomatic patients (t=2.760, P=0.007).And the proportion of LRNC plaqueswas lower than that in symptomatic patients (Z=2.009, P=0.044).There was statistical significance between the asymptomatic and symptomatic patients. Multivariate analysis showed that there was a positive correlation between the proportion of calcified plaques and asymptomatic carotid artery stenosis (OR=0.949; 95%CI: 0.915 to 0.985; P=0.005). The proportion of LRNC plaques showed a negative correlation with asymptomatic carotid artery stenosis (OR=1.068; 95%CI: 1.021 to 1.117; P=0.004). For the symptomatic patients, when the LRNC plaque proportion was greater than 30.3%, the specificity was 94.3%, and the sensitivity was 37.2%. There was no significant difference in plaque volume and fibrous plaque proportion in both groups. Conclusion： Compared with symptomatic carotid plaques, the proportion of asymptomatic calcified plaques increased but the proportion of LRNC plaques decreased. Plaque LRNC 30.3% of the total volume may represent a clinically useful cutoff. For the patients with carotid artery stenosis, MDCTA may help noninvasively risk-stratify patients.