Zhou Xiaowei, Xia Chunming, Stephen Gandy, Khan Faisel, Corner George A, Hoskins Peter R, Huang Zhihong
School of Science and Engineering, University of Dundee, Dundee, United Kingdom.
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China; NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom.
Ultrasound Med Biol. 2017 May;43(5):981-992. doi: 10.1016/j.ultrasmedbio.2016.12.015. Epub 2017 Feb 21.
Parameters of blood flow measured by ultrasound in radial and ulnar arteries, such as flow velocity, flow rate and wall shear rate, are widely used in clinical practice and clinical research. Investigation of these measurements is useful for evaluating accuracy and providing knowledge of error sources. A method for simulating the spectral Doppler ultrasound measurement process was developed with computational fluid dynamics providing flow-field data. Specific scanning factors were adjusted to investigate their influence on estimation of the maximum velocity waveform, and flow rate and wall shear rate were derived using the Womersley equation. The overestimation in maximum velocity increases greatly (peak systolic from about 10% to 30%, time-averaged from about 30% to 50%) when the beam-vessel angle is changed from 30° to 70°. The Womersley equation was able to estimate flow rate in both arteries with less than 3% error, but performed better in the radial artery (2.3% overestimation) than the ulnar artery (15.4% underestimation) in estimating wall shear rate. It is concluded that measurements of flow parameters in the radial and ulnar arteries with clinical ultrasound scanners are prone to clinically significant errors.
通过超声测量桡动脉和尺动脉血流的参数，如流速、流量和壁面切应力，在临床实践和临床研究中被广泛应用。对这些测量值进行研究有助于评估准确性并了解误差来源。利用计算流体动力学提供流场数据，开发了一种模拟频谱多普勒超声测量过程的方法。调整特定扫描因素以研究其对最大速度波形估计的影响，并使用沃默斯利方程推导流量和壁面切应力。当声束与血管夹角从30°变为70°时，最大速度的高估显著增加（收缩期峰值从约10%增至30%，时间平均值从约30%增至50%）。沃默斯利方程能够以小于3%的误差估计两条动脉的流量，但在估计壁面切应力时，在桡动脉（高估2.3%）比尺动脉（低估15.4%）表现更好。结论是，使用临床超声扫描仪测量桡动脉和尺动脉的血流参数容易出现具有临床意义的误差。
