基于线阵超声探头多波束并行发射的颈动脉血流多点频谱多普勒分析

Multi-Point Spectral Doppler Analysis of Carotid Artery Using Multi-Line Transmission with Linear Array Ultrasound Probe

目的在线阵超声探头上实现多波束并行发射,以进行颈动脉血流的多点频谱多普勒分析。方法在线阵探头上施加特定形式的脉冲发射延时和变迹,以实现多波束并行发射的效果,进而同时获取视野范围内多个位置采样体积的超声回波信号。通过仿真、仿体和在体实验,将该方法与目前临床广泛使用的单波束发射以及近年来引起关注的平面波发射进行性能比较。结果仿真和仿体实验中,三种发射模式的误差相当,仿真实验中单波束发射、多波束并行发射和平面波发射的流速估计相对误差分别为16%、16%和14%,仿体实验三种发射模式的相对误差分别为20%、18%和18%。在体实验中,多波束并行发射可以同时测量颈内动脉与颈总动脉的血流峰值流速;相较于平面波发射,多波束并行发射与单波束发射得到的频谱包络间的相关性更强;颈总动脉处,多波束并行发射和单波束发射得到的频谱包络间的相关系数(0.92)高于平面波发射和单波束发射间的相关系数(0.81);颈内动脉处,多波束并行发射和单波束发射得到的频谱包络间的相关系数(0.80)也高于平面波发射和单波束发射间的相关系数(0.71)。结论基于线阵超声探头的多波束并行发射是一种有效且便捷地进行颈动脉血流多点频谱多普勒分析的方法。

Objective To achieve multi-point spectral Doppler analysis of carotid artery using multi-line transmission on linear array ultrasound probe. Methods By applying specific transmission time delay and apodization on linear array probe, multiple beams were transmitted simultaneously to obtain the ultrasound echo signals of multiple sampling volumes. Multi-line transmission(MLT)was compared with single line transmission(SLT) and plane-wave imaging(PW) in computer simulations, phantom experiments and in vivo experiments. Results In the simulations and phantom experiments, the relative errors of velocity estimation using the above three transmission modes were comparable. The relative errors were 16%, 16% and 14% in the simulations and 20%, 18%, 18%in the phantom experiments for SLT, MLT and PW, respectively. In the in vivo experiments, MLT could measure the peak systolic velocities of common carotid artery and internal carotid artery simultaneously. In common carotid artery, the coefficient of correlation between the spectral envelopes obtained by MLT and SLT was 0.92, higher than that between the spectral envelopes obtained by PW and SLT(0.81). In internal carotid artery, the coefficient of correlation between the spectral envelopes obtained by MLT and SLT was0.80, also higher than that between the spectral envelopes obtained by PW and SLT(0.71). Conclusion Multi-line transmission with linear array probe is an effective and convenient approach for multi-point spectral Doppler analysis of carotid artery.