Effect of ultrasound on adherent microbubble contrast agents.
Effect of ultrasound on adherent microbubble contrast agents.
复制标题
超声对粘附微泡造影剂的影响。
DOI：
10.1088/0031-9155/57/21/6999
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发表时间：
2012
影响因子：
3.5
通讯作者：
Loughran J
中科院分区：
文献类型：
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作者：
Loughran J
临床超声暴露对粘附微泡的影响的调查。构建了一个流动体模，其中使用生物素-链霉亲和素连接附着靶向微泡。在一定压力范围内（峰值负压（PNP）= 60-375 kPa），通过宽带成像脉冲（中心频率为2.25 MHz）对微泡进行超声辐照。光学观察单个粘附气泡，并将其分类为孤立气泡或具有单个相邻气泡。结果发现，气泡分离和放气是两个显着的效果，即使在低振幅的超声暴露。具体而言，在非常低的声压（PNP< 75 kPa）下，95%的气泡不受影响，在中等压力（151 kPa< P< 225 kPa）下，53%的气泡脱离，在较高压力（301 kPa< P< 375 kPa）下，96%的气泡脱离。此外，超过50%的气泡在301和375 kPa之间的压力下经历放气。在226和300千帕之间的压力，更多的粘附气泡分离时，有一个相邻的气泡，这表明多重散射和二次Bjerknes力的气泡分离的作用。流剪切，初级和次级Bjerknes力施加在每个气泡上进行了计算，并比较的估计力作用在气泡上，由于振荡。振荡力被示出为比其他力高得多。讨论了气泡脱离的机理。
An investigation into the effect of clinical ultrasound exposure on adherent microbubbles is described. A flow phantom was constructed in which targeted microbubbles were attached using biotin–streptavidin linkages. Microbubbles were insonated by broadband imaging pulses (centred at 2.25 MHz) over a range of pressures (peak negative pressure (PNP)= 60–375 kPa). Individual adherent bubbles were observed optically and classified as either being isolated or with a single neighbouring bubble. It is found that bubble detachment and deflation are two significant effects, even during low amplitude ultrasound exposure. Specifically, while at very low acoustic pressure (PNP< 75 kPa) 95% of the bubbles were not affected, at medium pressure (151 kPa< P< 225 kPa) 53% of the bubbles detached and at higher pressures (301 kPa< P< 375 kPa) 96% of the bubbles detached. In addition, more than 50% of the bubbles underwent deflation at pressures between 301 and 375 kPa. At pressures between 226 and 300 kPa, more adherent bubbles detached when there was a neighbouring bubble, suggesting the role of multiple scattering and secondary Bjerknes force on bubble detachment. The flow shear, primary and secondary Bjerknes forces exerted on each bubble were calculated and compared to the estimated forces acting on the bubble due to oscillations. The oscillation force is shown to be much higher than other forces. The mechanisms of bubble detachment are discussed.