速度向量成像评价冠心病患者颈动脉粥样斑块力学特性的临床研究

Primary study of carotid atherosclerosis plaque biomechnics using ultrasonic velocity vector imaging in patients with coronary artery disease

目的探讨颈动脉正常和斑块部位、硬斑块和软斑块及斑块的肩部和纤维帽顶部速度、应变及应变率变化规律。方法对86例冠心病伴颈动脉粥样斑块患者和50例正常人双侧颈动脉进行高频超声检查，检测颈动脉内膜中层厚度（IMT）；应用速度向量成像（VVI）斑点追踪技术检测颈动脉的运动速度、应变、应变率，并分组进行分析。结果冠心病组颈动脉IMT高于正常组，差异有统计学意义（P〈0.05）；正常对照组颈动脉收缩期径向最大运动速度高于冠心病颈动脉无斑块部位的测值，差异有统计学意义（P〈0．05）；软斑块收缩期最大运动速度、最大应变率高于硬斑块组，差异有统计学意义（P〈0.001或P〈0.05）；颈动脉斑块肩部收缩期最大运动速度、应变率高于斑块纤维帽顶部，差异有统计学意义（P〈0.05或P〈0.001）。结论VVI技术可早期检测血管壁的弹性度，早期检测颈动脉粥样硬化及颈动脉粥样硬化斑块部位内膜运动的机械不一致性和不同部位的力学指标差别，有可能作为动脉粥样硬化不稳定斑块的初查和量化评价指标。

Objective To assess the changes of the velocity, strain and strain rate on the corresponding vascular of plaque and without plaque, hard plaque and soft plaque,the cupular part of fiber cowl and shoulder of plaque. Methods Eighty six patients with coronary artery disease（CAD） according to the results of coronary arteriography and 50 normal subjects underwent the high frequency ultrasound, and carotid artery intima media thickness（IMT） was detected. The velocity, strain and stain rate of carotid were obtained by velocity vector imaging（VVI） speckle tracking technique. Results The level of IMT in CAD patients was higher than that in normal control（ P〈0.05）. The systolic maximum velocity of carotid with normal contract was higher significantly than that of carotid without plaque with CAD（ P〈0.05）. The systolic maximum velocity and strain rate of soft plaque in carotid atherosclerosis were higher significantly than those of hard plaque （ P〈0. 001, P 〈0.05）. The maximum velocity and strain rate of fabric cowl in carotid atherosclerosis plaque were lower significantly than those of plaque shoulder （ P〈0.05, P〈0. 001 ）. Conclusions VVI technique could early detect the elasticity degree of blood vessel wall, artherosclerosis and the mechanism asynchrony of the plaque intima. The value difference could be used as the predictive parameter and quantization for artherosclerosis and plaque instability.