ASSESSMENT OF CAVITATION FROM DIAGNOSTIC ULTRASOUND

通过超声诊断评估空化

• 批准号: 3178259
• 负责人: ROBERT E APFEL
• 金额: $ 14.01万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1988-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3178259
• 关键词: biomedical equipment safety; luminescence; radiation hazard; ultrasonography; ultrasound biological effect; visible light

The use of ultrasound in diagnostic medicine has grown at a phenomenal rate in the last few years, and ultrasonic scanners are now readily available to physicians and health care professionals. Although there have been no clinically established health risks associated with diagnostic ultrasound, there has been some scientific evidence that even microsecond length pulses of high intensity ultrasound can produce cavitation in liquids and in biological systems (e.g. Drosophila larvae that have air-filled tracheae). Since microsecond-length pulses can only produce bubbles on the scale of single biological cells, it is necessary in assessing the likelihood of cavitation from diagnostic ultrasound to develop methods for monitoring this localized cavitation. Two complementary methods are proposed. In one, the aqueous medium used in these in vitro tests is seeded with superheated drops which will vaporize if cavitation occurs in or near them. These drop vaporizations [which are also employed in neutron detection] serve to amplify the localized cavitation events so that they can be measured with common acoustic techniques. The second technique not only measures the presence of cavitation but also the strength of a cavitation event by monitoring photons produced from either sonoluminescence or chemiluminescence (if luminol is disolved in the sample). By employing these techniques we will be able to delimit the conditions of pressure amplitude, frequency, pulse duration, and pulse repetition frequency in which cavitation can occur if gas nuclei of appropriate size and concentration are present. If some of these conditions overlap with the operating conditions of commercial diagnostic equipment, then we will determine if cavitation does indeed occur in vitro using this equipment as an acoustic source. Finally, if cavitation is still observed, we will make suggestions for some extensions of the present work to in vivo situations.

超声在诊断医学中的使用以惊人的速度增长 在过去的几年中，现在很容易使用超声波扫描仪 医师和医疗保健专业人员。 虽然没有 与诊断超声相关的临床确定的健康风险， 有一些科学证据表明即使是微秒长的脉冲 高强度超声可以在液体和 生物系统（例如，果蝇幼虫充满空气气管）。 由于微秒脉冲只能在尺度上产生气泡 单个生物细胞，有必要评估 从诊断超声到开发监测方法的空化 这个局部的空化。 提出了两种补充方法。 在 第一，将这些体外测试中使用的水介质与 过热的液滴，如果空化发生在或附近 他们。 这些下降蒸发[也用于中子 [检测]用于扩大局部空化事件，以便它们 可以用常见的声学技术来测量。 第二种技术不是 仅测量空气的存在，但也可以 通过监视从任何一个生产的光子监测光子的空化事件 发光或化学发光（如果将卢米尔溶解在 样本）。 通过采用这些技术，我们将能够界定 压力振幅，频率，脉冲持续时间和脉冲的条件 如果气体核的气体核可以发生重复频率 存在适当的尺寸和浓度。 如果其中一些 条件与商业诊断的运营条件重叠 设备，我们将确定是否确实在体外发生气态 使用此设备作为声源。 最后，如果空化为 仍然观察到，我们将为当前的一些扩展提出建议 在体内工作。