Accuracy and Reproducibility of a Novel Dual-Beam Vector Doppler Method

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• 作者：Stefano Ricci ; Stefano Diciotti ; Lorenzo Francalanci ; Piero Tortoli
• 关键词：Ultrasound ; Vector Doppler ; Dual-beam method ; Angle-dependence ; Blood velocity measurement ; Accuracy ; Reproducibility ; Carotid artery
• 刊名：Ultrasound in Medicine and Biology
• 出版年：2009
• 出版时间：May 2009
• 年：2009
• 卷：35
• 期：5
• 页码：829-838
• 全文大小：1349 K

文摘

Conventional Doppler ultrasound (US) investigations are limited to detect only the axial component of the blood velocity vector. A novel dual-beam method has been recently proposed in which the Doppler angle is estimated through a reference US beam, and the velocity magnitude through a measuring US beam, respectively. In this study, the performance of such a method has been assessed quantitatively through in vitro and in vivo measurements made in different experimental conditions. In vitro, more than 300 acquisitions were completed using seven transducers to insonify a straight tube phantom at different Doppler angles. In steady laminar flow conditions, the velocity magnitude was measured with mean error of –1.9 % (95 % confidence interval: –2.33 % to –1.47 % ) and standard deviation of 3.4 % , with respect to a reference velocity. In pulsatile flow conditions, reproducibility tests of the entire velocity waveforms provided an average coefficient of variation (CV) of 6.9 % . For peak velocity measurements made at five Doppler angles and three flow rates, the intrasession and intersession CVs were in the range 0.8–3.7 % and 2.9–10.6 % , respectively. The peak systolic velocities (PSVs) in the common carotid arteries of 21 volunteers were estimated with 95 % limits of agreement of ± 9.6 cm/s (intersession). This analysis shows that the proposed dual-beam method is capable of overcoming the Doppler angle ambiguity by producing reliable velocity measurements over a large set of experimental conditions. (E-mail: piero.tortoli@unifi.it)