CTA评价颈动脉斑块成分及体积与脑血管症状相关性

CTA Evaluation of Carotid Plaque Composition and Volume Correlation with Cerebral Vascular Symptoms

目的:采用CTA探讨脉颈动脉分叉部、颈内动脉虹吸段斑块成分和体积的差异、及其对脑血管事件的预测价值。方法:纳入行颈动脉CTA检查患者100人,其中男性65人,女性35人,平均年龄(55±9)岁。根据CT值的不同区分颈动脉分叉处及虹吸段斑块成分(脂质斑块<60 HU;混合斑块60~130 HU;钙化斑块>130 HU),并测量各成分斑块体积。分别使用独立样本T检验、x^2检验分析颈内动脉虹吸段与颈总动脉分叉部各组分斑块体积及构成比差异,并计算受试者工作特征曲线(ROC曲线)及其曲线下的面积,分析斑块总体积、各成分斑块体积对预测出现脑血管症状的准确性。结果:颈动脉分叉段与虹吸段斑块总体积分别为(752.3±3.4)mm^3,(56.2±5.541)mm^3,差异存在统计学意义(P<0.05)。颈内动脉虹吸段脂质斑块数量构成比为16.8%,钙化斑块数量构成比为49.1%,混合斑块数量构成比为34.1%;颈总动脉脂质斑块、钙化斑块、混合斑块数量构成比分别为33.3%,32.0%,34.6%,两处斑块数量构成比差异存在统计学意义(x^2=26.077,P<0.05)。ROC曲线分析显示颈动脉分叉斑块总体积、脂质斑块体积及混合斑块体积对脑血管症状的发生有较好的预测价值(P<0.001),曲线下面积分别为0.682、0.773及0.653,且颈动脉分叉脂质斑块体积为203.383 mm3时为最佳截割点,敏感度、特异度分别为69.0%、82.2%。结论:颈动脉分叉部和颈内动脉虹吸部不同类型斑块体积和构成比间有显著差异,颈动脉分叉部脂质斑块体积对脑血管事件有较好的预测价值。

Objective： The purpose of this work was to evaluate the differences of plaque composition and volume between carotid artery bifurcation and carotid siphon and its predictive value for cerebrovascular events. Materials and Methods： A total of 100 patients（65 men, 35 women; mean age,（55 ± 9） years） who underwent CT angiography experiment were enrolled. Plaque component types of the carotid artery bifurcation and the carotid siphon were defined depending on its attenuation values（lipid, 60 HU; mixed tissue, 60 ~ 130 HU; and calcification, 130 HU）, and the components volumes were calculated. Statistical analyses were performed using Student＇s t test and Chi-square test to evaluate the plaque volumes and constituent ratio difference among plaque components between carotid artery bifurcation and carotid siphon. The ROC curve and Az were calculated to evaluate the predict accuracy of the total and each component plaque volumes for cerebrovascular events. Result： There was a statistically significant difference（P 0.05） between the total volume of the carotid artery bifurcation（mean value,（752.3 ± 3.4） mm3） and the carotid siphon（mean value,（56.2 ± 5.541） mm3）） plaque. The constituent ratio of lipid, calcified, and mixed components were 16.8%, 49.1%, 34.1%, respectively, in the carotid artery bifurcation and 33.3%, 32.0%, 34.6%, respectively, in the carotid siphon, showing a statistically significant difference（？2= 26.077; P 0.05）. Statistical analysis approved the high predict accuracy of the carotid artery bifurcation total, lipid and mixed plaque volumes for cerebrovascular events with Az values of 0.682, 0.773, and 0.653, respectively. The best cut-point for the predict accuracy for cerebrovascular events in the plaque was 203.383 mm3 of fatty components, with sensitivity and specificity of 75% and 82%. Conclusion： Results of this study suggest there were significant differences in plaque volumes and constituent ratio among plaque components between carotid artery bifurcation and carotid siphon, and indicate the high predict accuracy of lipid plaque for cerebrovascular events.