脉冲多普勒超声血流定量测量的误差分析及新技术展望

Errors Analysis of Pulsed Wave Doppler Ultrasound Blood Flow Quantitative Measurement and New Technology Prospect

脉冲多普勒超声作为一种临床辅助诊断技术,广泛应用于血流的定量测量。但由于该技术直接得到的是沿超声传播方向的速度分量,实际测量时需要角度校正,因此容易产生误差。本文根据脉冲多普勒的计算方法和实现原理,从超声系统、算法和临床操作等多个方面详细阐述了脉冲多普勒超声定量测量可能产生的误差。重点对角度校正产生的误差做了详细的定量分析,并结合超声血流成像中的最大可测量速度、成像深度、发射信号的中心频率等多个相关参数,提出了避免或者减少误差的方法。最后指出一种可以避免这类误差但还未在临床上广泛使用的新技术,即超声向量血流成像。文章描述了这种新技术与传统脉冲多普勒的区别,介绍了新技术对于非层流定量测量的优势,并从临床的角度对向量血流成像当前问题和未来发展给出的意见和建议。

Pulsed-Wave(PW)Doppler ultrasound as a clinical diagnostic technique,is widely used for the quantitative measurement of blood flow.However,only the velocity component along the ultrasound propagation can be measured by PW,thus angle correction has to be made,which is prone to give rise to errors.In this paper,the potential errors of PW quantitative measurement are detailed from the aspects of ultrasound system,algorithm,clinical operation and so on,according to its formulation and implementation.The errors from the Doppler angle correction are quantified,and solutions to avoiding or reducing the errors are proposed in combination with the maximum detectable velocity,imaging depth,center frequency of emitting pulse and so on in ultrasound flow imaging.A new technology,which can avoid the presented errors but have not been widely used clinically yet,called vector flow imaging is introduced in the end.The difference between the new technology and conventional PW is described.The advantage of the new technology for the non-laminar flow quantative measurement is introduced.Comments and suggestions in terms of the current problems and future development of vector flow imaging from the clinical aspects,are elaborated in the paper.