Rickey D W, Fenster A
Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
Ultrasound Med Biol. 1996;22(6):747-66. doi: 10.1016/0301-5629(96)00045-2.
We describe two variations of a phantom designed to evaluate the wall filters implemented on colour and spectral Doppler instruments. Both variations use an acoustic beam splitter to place the same Doppler sample volume within a motor-driven clutter belt and a flow source, which is either a second belt (dual-belt phantom) or a vascular phantom (belt/vascular phantom). We used the dual-belt phantom to evaluate the effects of the clutter belt velocity, flow belt velocity and clutter-to-flow power ratio on the reported colour Doppler shifts. The results show that the choice of wall filter, as well as the amplitudes and velocities of the clutter and flow components, affect the measured Doppler shifts. Results obtained with the belt/vascular phantom show that colour Doppler shifts due to the moving fluid depend strongly on the clutter velocity and choice of wall filter. However, only a small dependence on Doppler signal strength was observed.
我们描述了一种用于评估彩色和频谱多普勒仪器上所实施的壁滤波器的体模的两种变体。两种变体均使用一个声束分离器，将相同的多普勒采样容积置于一个电机驱动的杂波带和一个流动源内，该流动源要么是另一个带（双带体模），要么是一个血管体模（带/血管体模）。我们使用双带体模来评估杂波带速度、流动带速度以及杂波与流动功率比对于所报告的彩色多普勒频移的影响。结果表明，壁滤波器的选择以及杂波和流动分量的幅度与速度，都会影响所测得的多普勒频移。使用带/血管体模所获得的结果表明，由流动液体引起的彩色多普勒频移强烈依赖于杂波速度和壁滤波器的选择。然而，仅观察到对多普勒信号强度有很小的依赖性。
