基于向量速度的阻力指数计算和对比及校正方法研究

Calculation and Comparison of the Resistance Index Based on Vector Velocities and Correction Method Studies

摘要: 阻力指数是超声临床评估血流动力学变化的重要指标之一。该研究目的在于评估一种新的超声检查模式——向量血流成像功能在测量该指标时的可靠性。通过对10例健康志愿者双侧颈总动脉起始段、中段、末段共6个位置分别采集数据，得到的RI值计算结果与传统PW方式误差约12%。根据向量速度的方向对PW测值校正后，两者的相对误差及其方差均有所下降。基于向量血流成像，用户无需手动校正角度即可直接得到实际流速；除RI计算外，还可对不同时刻的血流速度角度差进行对比，更直观地了解血流动力学细节信息。

Abstract: Resistance Index (RI) is one of the indicators for ultrasound evaluation of hemodynamic changes. The purpose of this study is to evaluate the reliability of V Flow, which is a new ultrasound examination, when calculating this index. Data were collected from six positions of the bilateral common carotid artery (CCA) at the beginning, middle, and end of 10 healthy volunteers. The result shows that the RI error between V Flow and PW is about 12%. After angle correction for PW results both the relative error and its variance is reduced. Based on V Flow, users can directly obtain the actual flow velocity without manually correcting the angle. In addition to RI, blood flow velocity angle at different times can be compared to more intuitively to understand the hemodynamic details.