Controlled ultrasound tissue erosion: The role of dynamic interaction between insonation and microbubble activity
Controlled ultrasound tissue erosion: The role of dynamic interaction between insonation and microbubble activity
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DOI：
10.1121/1.1828551
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发表时间：
2005-01-01
影响因子：
2.4
通讯作者：
Cain, CA
中科院分区：
文献类型：
--
作者：
Xu, Z;Fowlkes, JB;Cain, CA
先前的研究表明，超声可以以局部、可控的方式机械地去除组织。此外，增强的声学后向散射与侵蚀过程高度相关。本文研究了这种强后向散射环境的“引发”和“熄灭”。引发和侵蚀之间的关系，引发和灭绝的变化，以及脉冲强度和气体饱和度对时间的影响，以引发（引发延迟时间）进行了研究。使用788 kHz单元件换能器。施加3周期脉冲持续时间和20 kHz脉冲重复频率的多个脉冲。I-SSPA值在1000和9000 W/cm（2）之间，气体饱和度范围为24%-28%、39%-49%和77%-81%。结果表明：（1）在没有引发的情况下，从未观察到侵蚀;（2）高度反向散射环境的引发和熄灭本质上是随机的并且取决于声学参数;（3）引发延迟时间随着较高强度和较高气体饱和度而较短（例如，平均引发延迟时间在4000 W/cm（2）的I-SSPA下为66.9 s，在9000 W/cm（2）的I-SPPA下为3.6 ms;（4）一旦由高强度脉冲引发，可以使用比引发过程所需的强度显著更低的强度来维持高度反向散射环境和侵蚀。(C)2005年美国声学学会。
Previous studies showed that ultrasound can mechanically remove tissue in a localized, controlled manner. Moreover, enhanced acoustic backscatter is highly correlated with the erosion process. "Initiation" and "extinction" of this highly backscattering environment were studied in this paper. The relationship between initiation and erosion, variability of initiation and extinction, and effects of pulse intensity and gas saturation on time to initiation (initiation delay time) were investigated. A 788-kHz single-element transducer was used. Multiple pulses at a 3-cycle pulse duration and a 20-kHz pulse repetition frequency were applied. I-SSPA values between 1000 and 9000 W/cm(2) and gas saturation ranges of 24%-28%, 39%-49%, and 77%-81% were tested. Results show the following: (1) without initiation, erosion was never observed; (2) initiation and extinction of the highly backscattering environment were stochastic in nature and dependent on acoustic parameters; (3) initiation delay times were shorter with higher intensity and higher gas saturation (e.g., the mean initiation delay time was 66.9 s at I-SSPA of 4000 W/cm(2) and 3.6 ms at I-SPPA of 9000 W/cm(2)); and (4) once initiated by high-intensity pulses, the highly backscattering environment and erosion can be sustained using a significantly lower intensity than that required to initiate the process.) (C) 2005 Acoustical Society of America.