Miller Douglas L, Dou Chunyan, Wiggins Roger C
Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109-0553, USA.
J Acoust Soc Am. 2007 Oct;122(4):2002-8. doi: 10.1121/1.2773991.
Research on cavitational bioeffects of diagnostic ultrasound (DUS) typically involves a diagnostic scanner as the exposure source. However, this can limit the ranges of exposure parameters for experimentation. Anesthetized hairless rats were mounted in a water bath and their right kidneys were exposed to ultrasound. Amplitude modulation with Gaussian envelopes simulated the image pulse sequences (IPSs) produced by diagnostic scanning. A 10 mulkgmin IV dose of Definity((R)) contrast agent was given during 1-5 min exposures. Glomerular capillary hemorrhage was assessed by histology. A stationary exposure approximated the bioeffects induced by DUS within the beam area. However, the use of five closely spaced exposures more faithfully reproduced the total effect produced within a DUS scan plane. Single pulses delivered at 1 s intervals induced the same effect as the simulated DUS. Use of 100 ms triangle-wave modulations for ramp-up or ramp-down of the IPS gave no effect or a large effect, respectively. Finally, an air-backed transducer simulating DUS without contrast agent showed a zero effect even operating at twice the present DUS guideline upper limit. Relatively simple single-element laboratory exposure systems can simulate diagnostic ultrasound exposure and allow exploration of parameter ranges beyond those available on present clinical systems.
诊断超声（DUS）的空化生物效应研究通常使用诊断扫描仪作为暴露源。然而，这可能会限制实验中暴露参数的范围。将麻醉后的无毛大鼠置于水浴中，其右肾暴露于超声下。用高斯包络进行幅度调制模拟诊断扫描产生的图像脉冲序列（IPS）。在1 - 5分钟的暴露期间，静脉注射10微升/千克/分钟的Definity®造影剂。通过组织学评估肾小球毛细血管出血情况。静态暴露近似于DUS在波束区域内诱导的生物效应。然而，使用五次紧密间隔的暴露能更忠实地再现DUS扫描平面内产生的总效应。以1秒的间隔发送单个脉冲所产生的效果与模拟DUS相同。对IPS进行上升或下降的100毫秒三角波调制分别没有效果或有很大效果。最后，模拟无造影剂DUS的空气背衬换能器即使在当前DUS指南上限的两倍下运行也显示出零效应。相对简单的单元素实验室暴露系统可以模拟诊断超声暴露，并允许探索超出当前临床系统可用参数范围的参数。
