ULTRASONIC GENERATION OF MICROBUBBLES FOR DIAGNOSIS

用于诊断的超声波产生微泡

• 批准号: 2142217
• 负责人: PAUL L CARSON
• 金额: $ 15.52万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2142217
• 关键词: biomedical equipment development; cardiography; clinical biomedical equipment; cystoscopy; diagnosis design /evaluation; disease /disorder model; dogs; heart disorder diagnosis; image enhancement; imaging /visualization /scanning; interstitial cystitis; noninvasive diagnosis; technology /technique development; ultrasonography; urinary bladder; urinary tract disorder diagnosis; urinary tract imaging /visualization

The general goals of this research are the same as the previous proposal, to develop techniques for minimally invasive bubble generation, growth and maintenance in vivo. A specific application, diagnosis of urinary reflux has now been targeted for development and preliminary, complimentary investigations will be performed on a second medical applications, diagnosis of interstitial cystitis. The first grant period has been one in which almost all the necessary elements of noninvasive ureteral vesicular reflux diagnosis have been shown to be feasible. Some techniques of bolus generation for blood flow and perfusion imaging also have been demonstrated, but will not be pursued further here. For reflux, apparently noninvasive acoustic generation of bubbles has been demonstrated in the fresh, full dog bladder under conditions which should be more difficult than the in vivo case. In albumin-stabilized microbubbles, with still less than optimal techniques, we have demonstrated acoustically-induced growth in backscatter of as much as 15 dB in the 2-3 MHz frequency range wit a 0.5s, 1 MPa, swept-frequency pulse. More importantly, calculations of rectified diffusion of free bubbles show a 60 fold increase in backscatterat the peak frequency (in 1 sec, 0.4 MPa frequency priches), with great narrowing of the backscattered frequency distribution to 2.8% of the resonant frequency. Additionally our experiments with static depressurization show greatly restricted diffusion into albumin-stabilized microbubbles, indicating that we should be able to grow free bubbles in the bladder at much faster rates than we have now demonstrated in stabilized microbubbles. Acoustic trapping and movement of a limited quantity of bubbles to a simulated bladder orifice has been demonstrated as has trapping of bubbles in the beam in an in situ canine bladder. Finally, we have demonstrated in vivo that even early reflux can be diagnosed acoustically given adequate stabilized microbubbles in the bladder. This proposal is directed to careful, quantitative research to make ureteral vesicular reflux diagnosis easily workable. We propose to determine a simple and robust method of generating and characterizing copious quantities of bubbles in appropriately pure water, test the techniques on a wide range of urine properties in excised bladders representing in vivo conditions, and test the bubble generation and control and reflux diagnosis in an in vivo animal model. A search for acoustic/bubble conditions to cause bladder wall irritation in an animal model, with and without cystitis, will be undertaken to aid development of reflux diagnosis with low risk of immediate effects and to initiate investigation of possible methods of diagnosing interstitial cystitis.

本研究的总体目标与之前的建议相同， 开发微创气泡生成、生长 和体内维持。 泌尿系疾病的具体应用、诊断 回流现在已经成为发展和初步的目标， 将在第二次体检中进行补充调查 间质性膀胱炎的诊断 第一批赠款 几乎所有非侵入性的必要元素 输尿管小泡反流诊断已被证明是可行的。 一些 用于血流和灌注成像的团生成技术还 已经证明，但在此不再进一步探讨。 为 反流，显然是无创的声学产生的气泡已经被 在新鲜的、充满的狗膀胱中证明， 比在体内的情况更困难。 在白蛋白稳定 微泡，仍然低于最佳技术，我们有 在反向散射中表现出多达15 dB，2-3 MHz频率范围，0.5s，1 MPa，扫频 脉搏了 更重要的是，计算整流扩散的自由 气泡显示在峰值频率处（以 1秒，0.4 MPa频率穿刺）， 后向散射频率分布为谐振频率的2.8%。 此外，我们的静态降压实验表明， 限制扩散到白蛋白稳定的微泡中，表明 我们应该能够更快地在膀胱中产生自由气泡 比我们现在在稳定的微泡中证明的速率更高。 声学 捕获和移动有限数量的气泡到模拟的 膀胱口已经被证明是气泡在 在原位犬膀胱中的光束。 最后，我们在体内证明了 即使是早期的返流也可以通过声学诊断， 稳定膀胱中的微泡。 这项建议是针对仔细，定量研究，使 输尿管小泡反流诊断容易可行。 我们建议 确定一种简单而强大的生成和表征方法 大量的气泡在适当的纯净水，测试 在离体膀胱中广泛的尿液性质的技术 代表体内条件，并测试气泡生成， 在体内动物模型中的控制和反流诊断。 搜索 引起动物膀胱壁刺激的声学/气泡条件 模型，有和没有膀胱炎，将进行援助发展 反流诊断的低风险的直接影响，并开始 间质性膀胱炎的诊断方法探讨。