SGER: Dynamics of Encapsulated Microbubbles for Medical Ultrasound

SGER：用于医学超声的封装微泡的动力学

• 批准号: 0352829
• 负责人: Kausik Sarkar
• 金额: $ 4万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-15 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0352829&HistoricalAwards=false
• 关键词: SGER; Dynamics; Encapsulated; Microbubbles; Medical

AbstractCTS-0352829K. Sarkar, University of DelawareMicrobubbles are intravenously introduced into a patient's body to enhance the contrast of an ultrasound image. Our aim is to develop a reliable mathematical model for these microbubble contrast agents and characterize different agents with it. Specifically the focus of the modeling is the protective encapsulation of a contrast microbubble made of lipids, proteins or surfactants. Even though free microbubbles (without encapsulation) perform much better in reflecting ultrasound and enhancing image contrast, they issolve in blood stream in few seconds. The encapsulation stabilizes them making contrast imaging possible. Technical merit: A new interface model for the encapsulation with surface rheological properties will be developed. These properties will be determined by in vitro attenuation experiments with clinically approved contrast agents Definity and Optison. We claim that the proposed model of absorbed interface contains the essential physics, and will remain valid over a wider range of frequency and amplitude. We will test this hypothesis by comparing model predictions with scattering experiments (different from those used for model determination). The model parameters will be determined using a linearized version of the model appropriate for experiments with pulses of less energy. However, the developed models nonlinear dynamics will be compared with measured harmonic and subharmonic emissions. Our preliminary modeling with experimental data available in the literature for Optison shows encouraging agreement with measured subharmonic emission. We are collaborating on the clinical implementation of our research with Professors Flemming Forsberg and Barry Goldberg, MD of the Radiology Department at Thomas Jefferson Medical College and Hospital. Beyond contrast ultrasound the proposed research will provide critical understanding of interface dynamics in colloids and suspensions. Broader Impact: Ultrasound examination is the safest and the most popular means of imaging (one in every three imaging studies performed in the world is an ultrasound test). Utility of ultrasonography images however is limited due to poor contrast. For instance, 20 percent of the 17 million echocardiography performed in the United States in 2000 were suboptimal, i.e. did not provide definitive diagnosis for coronary heart disease. A good contrast agent will enable reliable imaging of abnormal blood flows leading to early reliable diagnosis. Use of contrast agent is not limited to heart; it also includes imaging kidney, liver and brain. Development of effective contrast agents and efficient modality can only be achieved through in vitro research with clinical collaboration such as proposed here. The proposed characterization will be used to provide useful guidelines to agent developers (e.g. Amersham Health, Bristol Myers Squibb) and scanner manufacturers (e.g. GE). The research will involve engineering graduate and undergraduate students in a non-traditional cross-disciplinary science of medical imaging.

Abstractcts-0352829K。 Sarkar，Delawarememecubbles静脉注射到患者体内，以增强超声图像的对比度。 我们的目的是为这些微气泡对比剂开发可靠的数学模型，并用它来表征不同的代理。具体来说，建模的重点是对脂质，蛋白质或表面活性剂制成的对比度微泡的保护性封装。即使自由微泡（无封装）在反射超声波和增强图像对比度方面的表现要好得多，但它们在几秒钟内就在血液中发出。 封装使它们稳定，使对比度成像成为可能。 技术优点：将开发出具有表面流变特性的新接口模型。这些特性将通过具有临床认可的对比剂定义和Optison的体外衰减实验来确定。我们声称所提出的吸收界面模型包含必需物理，并且在频率和振幅范围更大的范围内保持有效。 我们将通过将模型预测与散射实验进行比较（与用于模型确定的模型不同）来检验这一假设。 模型参数将使用适用于具有较少能量的脉冲的实验的模型的线性化版本确定。但是，开发的模型非线性动力学将与测得的谐波和亚谐波排放进行比较。 我们的初步建模与Optison文献中可用的实验数据相同，表明与测量的亚谐波排放达成了令人鼓舞的一致性。我们正在与托马斯·杰斐逊医学院和医院放射学系的医学博士Flemming Forsberg和Barry Goldberg教授合作进行研究。除对比度超声波外，提出的研究将提供对胶体和悬浮液中界面动力学的批判性理解。 更广泛的影响：超声检查是最安全，最受欢迎的成像方法（世界上每三个成像研究中的一项是超声测试）。 但是，由于对比度不佳，超声图像的效用受到限制。 例如，在2000年在美国进行的1700万超声心动图中，有20％是次优的，即没有为冠心病提供明确的诊断。良好的对比剂将使异常流动的可靠成像可靠，导致早期可靠的诊断。使用造影剂不限于心脏；它还包括成像肾脏，肝脏和大脑。 有效的对比剂和有效方式的开发只能通过在此处提出的临床协作的体外研究来实现。拟议的表征将用于为代理开发人员（例如Amersham Health，Bristol Myers Squibb）和扫描仪制造商（例如GE）提供有用的准则。 这项研究将涉及工程学毕业生和本科生的医学成像跨学科科学。