The Doppler ultrasound twinkling artifact, a rapid color shift, appears on pathological mineralizations and is theorized to arise from scattering off micron-sized crevice microbubbles. However, the influence of crevice number and size as well as the bubble dynamics on twinkling is not well-understood. Cylinders with diameters of 0.8–1.2 µm and depths of 1 µm were etched into a silicon wafer and crevice bubbles were driven at 0.75, 2.5, and 5.0 MHz while monitoring with high-speed photography. Experimental results were compared to a derived crevice bubble model. On three separate wafers, cylindrical crevices (10 or 100) with diameters of 1, 10, or 100 µm and depths of 10 µm were etched and imaged with a research ultrasound system in Doppler mode at 5, 7.8, and 18.5 MHz. Within the pressure ranges studied here (∼1MPa), no bubble oscillation was observed for the 0.8–1.2 µm crevice bubbles which matched computational results. Crevices with 1 and 10 µm diameters produced more twinkling than 100 µm crevices at 5 and 7.8 MHz. In contrast, 100 µm crevices produced more twinkling than 1 or 10 µm crevices at 18.5 MHz (p < 0.001 in all cases). These results provide better insight into how crevice bubbles cause twinkling on pathological mineralizations.

中文翻译：

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导致闪烁伪影的缝隙微泡的动力学


多普勒超声闪烁伪像是一种快速的颜色变化，出现在病理性矿化上，理论上是由微米级缝隙微泡的散射产生的。然而，缝隙数量和尺寸以及气泡动力学对闪烁的影响尚不清楚。将直径为 0.8–1.2 µm、深度为 1 µm 的圆柱体蚀刻到硅晶片中，并以 0.75、2.5 和 5.0 MHz 驱动缝隙气泡，同时用高速摄影进行监测。将实验结果与导出的缝隙气泡模型进行比较。在三个独立的晶圆上，蚀刻直径为 1、10 或 100 µm、深度为 10 µm 的圆柱形缝隙（10 或 100 个），并使用研究超声系统在多普勒模式下以 5、7.8 和 18.5 MHz 进行成像。在此研究的压力范围内 (∼1MPa)，没有观察到 0.8–1.2 µm 缝隙气泡的气泡振荡，这与计算结果相符。在 5 和 7.8 MHz 下，直径为 1 和 10 µm 的缝隙比 100 µm 缝隙产生更多闪烁。相比之下，在 18.5 MHz 下，100 µm 缝隙比 1 或 10 µm 缝隙产生更多闪烁（在所有情况下 p < 0.001）。这些结果可以更好地了解缝隙气泡如何导致病理矿化闪烁。