Threshold of fragmentation for ultrasonic contrast agents
Threshold of fragmentation for ultrasonic contrast agents
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DOI：
10.1117/1.1352752
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发表时间：
2001-04-01
影响因子：
3.5
通讯作者：
Ferrara, K
中科院分区：
文献类型：
--
作者：
Chomas, JE;Dayton, P;Ferrara, K
超声对比剂是小的微泡，可以通过足够的声压很容易破坏，通常在低兆赫兹范围内的频率下。微血管流速可以通过在血管床中破坏造影剂，并估算造影剂的流动速率回到血管床中来估算微血管流速。对比剂破坏的表征为该技术的设计提供了重要信息。在本文中，进行了声音震荡期间对超声对比剂的高速光学观察。静息直径被证明是预测微泡破坏的重要参数，较小的直径通常与破坏相关。压力，中心频率和传输阶段都显示对碎裂阈值具有显着影响。碎裂阈值作为压力的函数的线性预测，当通过静止直径标准化时，对于从310到1200 kPa的压力范围，变化率为300 kpa/妈妈，并且具有2.25 MHz的中心频率的两循环激发脉冲。片段化阈值作为频率的函数的线性预测，当通过静止直径归一化时，对于800 kPa的透射压力，变化速率为-1.2 MHz/MUM，并且具有从1到5 MHz的频率范围的两周期激发脉冲。 （c）2001光学仪器工程师学会。
Ultrasound contrast agents are small microbubbles that can be readily destroyed with sufficient acoustic pressure, typically, at a frequency in the low megaHertz range. Microvascular flow rate may be estimated by destroying the contrast agent in a vascular bed, and estimating the rate of flow of contrast agents back into the vascular bed. Characterization of contrast agent destruction provides important information for the design of this technique. In this paper, high-speed optical observation of an ultrasound contrast agent during acoustic insonation is performed. The resting diameter is shown to be a significant parameter in the prediction of microbubble destruction, with smaller diameters typically correlated with destruction. Pressure, center frequency, and transmission phase are each shown to have a significant effect on the fragmentation threshold. A linear prediction for the fragmentation threshold as a function of pressure, when normalized by the resting diameter, has a rate of change of 300 kPa/mum for the range of pressures from 310 to 1200 kPa, and a two-cycle excitation pulse with a center frequency of 2.25 MHz. A linear prediction for the fragmentation threshold as a function of frequency, when normalized by the resting diameter, has a rate of change of -1.2 MHz/mum for a transmission pressure of 800 kPa, and a two-cycle excitation pulse with a range of frequencies from 1 to 5 MHz. (C) 2001 Society of Photo-Optical Instrumentation Engineers.