ACOUSTIC GENERATION OF BUBBLES IN EXCISED CANINE URINARY BLADDERS
ACOUSTIC GENERATION OF BUBBLES IN EXCISED CANINE URINARY BLADDERS
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DOI：
10.1121/1.400713
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发表时间：
1991-06-01
影响因子：
2.4
通讯作者：
RUBIN, JM
中科院分区：
文献类型：
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作者：
FOWLKES, JB;CARSON, PL;RUBIN, JM
使用高强度的555 kHz声场在从狗切除的膀胱内产生气泡。 暴露后，在带有5 MHz在线机械扇形扫描头的诊断超声扫描仪上观察气泡。 在暴露过程中也观察到高强度超声被气泡散射为高振幅扫描线。 所使用的膀胱在结扎输尿管和尿道后被手术切除，以防止尿液流失和暴露于外部污染物。 将每个囊密封在填充有脱气盐水溶液的塑料袋中。 囊位于密封脱气水路径的中心，位于7 cm直径换能器和10 cm直径黄铜反射器的共同焦点处。 555-kHz换能器和反射器都聚焦在10 cm处，并同轴对齐。 使用不同的声压振幅，两个，10秒的低频曝光，约30秒分开，发生在约2分钟的时间间隔。 在一个单一的膀胱实验持续了长达45分钟。最大的气泡，这是很容易成像的大小，估计从上升速度测量为50-70 μ m的半径，和用于产生这些大气泡的压力幅度估计为10-20巴。 较小气泡的检测受限于无法清楚地区分气泡回波与由膀胱内的混响场引起的伪影。 目视检查的外部和内部膀胱壁内的高强度光束path. Results没有显着的变色，这项研究表明，气泡可能会产生在体内从外部来源可能用作回声造影剂和研究声空化的生物效应。
A high-intensity, 555-kHz acoustic field was used to generate bubbles within urinary bladders excised from dogs. Following the exposure, bubbles were visualized on a diagnostic ultrasound scanner with a 5-MHz in-line mechanical sector scanhead. Scattering of the high-intensity ultrasound by the bubbles was also observed during the exposure as high-amplitude scan lines. The bladders used had been surgically removed after tying off the ureters and urethra to prevent urine loss and exposure to external contaminants. Each bladder was sealed in a plastic bag filled with a degassed saline solution. The bladder was centered in a sealed degassed water path at the common focus of a 7-cm-diam transducer and a 10-cm-diam brass reflector. The 555-kHz transducer and reflector were both focused at 10 cm and were aligned coaxially. Using various acoustic pressure amplitudes, two, 10-s low-frequency exposures, separated by approximately 30 s, occurred at approximately 2-min intervals. Experiments on a single bladder lasted as long as 45 min. The sizes of the largest bubbles, which were easily imaged, were estimated from rise velocity measurements as 50-70-mu-m in radius, and pressure amplitudes used to generate those large bubbles were estimated as 10-20 bars. The detection of smaller bubbles was limited by the inability to clearly distinguish bubble echoes from artifacts caused by the reverberant field within the bladder. Visual inspection of the exterior and interior bladder wall showed no significant discoloration within the high intensity beam path. Results of this study indicate that bubbles might be generated in vivo from external sources for possible use as echo contrast agents and for studying the bioeffects of acoustic cavitation.