孤立性颈动脉粥样硬化斑块内膜旋转角度的超声评价

Assessment of Carotid Plaque Rotation Angle Using Ultrasonic Imaging

目的应用超声速度向量技术检测孤立性颈动脉粥样硬化斑块内膜旋转的发生和角度变化,为临床评价颈动脉粥样硬化斑块内膜力学状态提供新的技术方法。方法采用超声速度向量成像技术,检测并量化评价46例患者共48个孤立性偏心性粥样硬化斑块内膜旋转运动及其角度,比较标准等长握力试验前后孤立性颈动脉粥样硬化斑块上、中、下游不同部位和正常参考段血管短轴收缩期和舒张期内膜旋转的发生频率和旋转角度。结果多数孤立性动脉粥样硬化斑块和参考段血管内膜表面在心动周期中均发生了旋转运动;上述节段动脉内膜在收缩期和舒张期的旋转运动方向相反。握力试验前收缩期斑块上游段动脉内膜旋转运动的发生率明显高于参考段动脉(P=0.036)。握力试验后舒张期斑块中游段动脉内膜旋转运动的发生率明显低于参考段动脉(P=0.031)。握力试验前后斑块上、中、下游段动脉内膜旋转运动的发生率均发生变化,多为收缩期增加、舒张期减少;参考段动脉内膜旋转运动的发生率未发生任何变化。结论多数孤立性颈动脉粥样硬化斑块内膜在收缩和舒张期分别发生了与正常颈动脉内膜不同的旋转运动,其中颈动脉斑块和正常内膜在握力试验前后收缩和舒张期发生的旋转运动差异有可能被应用于提示孤立性颈动脉粥样硬化斑块内膜的不稳定力学状态。

Objective To demonstrate the abnormal intima rotation pattern of the carotid atherosclerosis plaque using velocity vector imaging, and to develop a new method for the clinical mechanical state assessment of the plaque intima. Methods The rotation movement and rotation angle on the serial dynamic ultrasonic short-axis gray scale views of 48 isolated atherosclerosis plaques （ i. e. , upstream, midstream, and down- stream） and nearby reference segments of carotid artery in 46 patients were derived and analyzed using a dedi- cated velocity vector imaging workstation. The incidence of intima rotation movement and the rotation angle at different sections of the plaque and nearby reference segments before and after the standard grip stress test during systole and diastole respectively were counted and measured. Results Before and after the stress test, the intima rotation movement occurred at the majority of the short-axis sections of the plaque and the nearby refer- ence segments during cardiac cycle. Before the stress test, the incidence of intima rotation movement at the up- stream section of the plaque during systole was significantly higher than that of reference segment （ P =0. 036 ）The reversal direction of the intima rotation at significantly higher than that of reference segment （ P = 0. 036 ） those sections and reference segment during systole and diastole was demonstrated. After the stress test, the incidence of intima rotation movement at the midstream section of the plaque during diastole was significan the intima rotation movement changed a tly lower than that of reference segment （ P = 0. 031 ）. The incidence of t the sections of upstream, midstream, and downstream of the plaque before and after the stress test also were explored （ i. e. , increased in systole and decreased in diastole） except the reference segment intima. Conclusions The intima rotation movement occurs at the majority of the isolated plaque and nearby reference segment, and the incidences of the intima rotation movement at the plaque is different from that of the reference segment during systole and diastole respectively. The abnormal pattern of intima rotation movement may be used to indicate the unstable mechanical state of the isolated plaque intima.