超微血管显像技术评价颈动脉粥样硬化斑块新生血管及病理对照分析

Comparison between superb microvascular imaging and histopathology for the evaluation of carotid artery atherosclerotic plaque neovascularization

目的评价超微血管显像(superb microvascular imaging,SMI)技术检测颈动脉硬化斑块内新生血管的应用价值。方法对28例颈动脉内膜切除术患者行SMI检测,共检测到颈动脉粥样硬化斑块28例。SMI技术将颈动脉斑块内新生血管分为4级:未见新生血管为0级,点状新生血管为1级,斑块肩部或基底部可见点状或1~2条线状新生血管或可测到频谱为2级;多条(>2条)线状新生血管贯穿斑块并可测到频谱为3级。评估SMI显示斑块内新生血管的血流丰富程度、新生血管的最高流速及阻力指数。病理样本采用CD31染色法进行超微血管密度测定。结果SMI技术检测的血管丰富程度分级与组织病理染色斑块内新生血管密度存在明显相关性(rs=0.788,P<0.001)。SMI对斑块新生血管丰富程度的分级与斑块厚度呈正相关(rs=0.686,P=0.002)。28例中,23例可探及新生血管,其中17例(75%)为血流方向为自外膜到内膜,6例(25%)为血流方向走形不规则,新生血管流速平均值为(5.620±0.131)cm/s,新生血管平均阻力指数为0.660±0.090。结论SMI技术对于评估颈动脉粥样硬化斑块内新生血管有临床应用前景。

Objective To investigate the significance of superb microvascular imaging (SMI) for the detection of neovascularization in carotid atherosclerotic plaques. Methods SMI detected 28 carotid atherosclerotic plaques in 28 patients who underwent carotid endarterectomy. The SMI grade of carotid plaque neovascularization was assigned based on the following grading system: Grade 0, no neovascularization;grade 1, some neovascularization;grade 2, neovascularization observed in the shoulder of the plaque;and grade 3, widely distributed new blood vessels. SMI was used to evaluate the degree of blood flow, maximum flow velocity, and resistance index of the new vessels in the plaque. Microvascular density was measured with CD31 staining. Results Clear correlations were observed between neovascularization density on histopathological staining of the plaque and the degree of blood flow detected with SMI (rs=0.788, P < 0.001). The classification of neovascular blood flow in the plaque was positively correlated with plaque thickness (rs=0.686, P=0.002). Of the 28 cases, neovascularization was detected in 23;of these 23 cases, the direction of blood flow was from the adventitia to the intima in 17 (75%) cases, while 6 (25%) cases showed an irregular direction of blood flow. The mean neovascular flow velocity was (5.620±0.131) cm/s, and the mean neovascular resistance index was 0.660±0.090. Conclusion SMI is useful for the evaluation of carotid atherosclerotic plaque neovascularization.