Advanced Polymeric Tissue-Mimicking Materials and Phantoms for Evaluation of Multispectral Photoacoustic Imaging Systems

用于评估多光谱光声成像系统的先进聚合物组织模拟材料和模型

基本信息

批准号：
1842387
负责人：
Jesse Jokerst
金额：
$ 10万
依托单位：
University of California-San Diego
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1842387&HistoricalAwards=false
关键词：
Advanced Polymeric Tissue Mimicking Materials

项目摘要

NON-TECHNICAL SUMMARYUltrasound is a powerful tool to image diseases including cancer, orthopedic disorders, and heart function. One limitation of ultrasound is that it suffers from low contrast between the region of interest versus the background tissue. Therefore, there is a wide body of research into a special kind of ultrasound known as photoacoustic imaging. Photoacoustic imaging uses light to generate sound only in the area of interest. This increases the contrast. Unfortunately, photoacoustic ultrasound is not yet approved for widespread use in people. This might be partially due to a lack of standardization devices and methods to validate the novel imaging equipment that is needed for photoacoustic imaging. Therefore, this proposed work will create specialized plastic objects with known optical and acoustic properties suitable for calibrating and standardizing photoacoustic imaging equipment. This proposal combines expertise from academia and the Food and Drug Administration to create test objects and methods that will be useful to instrument manufacturers and physicians. The resulting test objects will improve knowledge of how to best create photoacoustic imaging instrumentation and might also streamline regulatory approval of this equipment. In turn, this will increase patient access to this important imaging technique to ultimately advance the national health and quality of life. TECHNICAL SUMMARYPhotoacoustic imaging provides deep tissue imaging similar to ultrasound but with enhanced optical contrast and additional functional and molecular imaging capabilities. However, no standardized performance test methods or phantoms exist for photoacoustic imaging system evaluation unlike mature techniques (ultrasound, MRI, CT). The fundamental limitation is a lack of materials to simultaneously simulate tissue properties over a broad range of optical wavelengths and acoustic frequencies. This leaves investigators, instrument manufacturers, and regulatory agencies without clear strategies to evaluate device safety and effectiveness. This proposed work will create stable, biologically relevant imaging phantoms with well-characterized optical absorption/scattering coefficients, acoustic impedance, etc. that broadly simulate tissue over a wide range of optical wavelengths and acoustic frequencies. A literature search and laboratory study will identify suitable materials such as polyacrylamide hydrogels or novel polyvinyl chloride plastisol formulations. Intrinsic properties will be measured using well-validated spectrophotometry and acoustic pulse transmission methods and equipment at FDA. Once the phantom material formulations have been optimized, we will construct phantoms in several specific configurations to evaluate image quality metrics such as spatial resolution, penetration depth, etc. These novel phantoms will then be used with three photoacoustic systems with substantially different operating parameter ranges (e.g. optical wavelengths). Image quality metrics will be compared between devices to elucidate performance trade-offs between systems and the overall impact of system design choices and phantom properties on performance. The goal is to produce phantoms with 6-month stability that spectrally mimic hemoglobin and deoxyhemoglobin and contain targets that enable image quality testing. The outcome will be a well-validated tissue-mimicking phantom to support device developers and inform regulatory decision-making including use as potential FDA Medical Device Development Tools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术总结是图像疾病，包括癌症，骨科疾病和心脏功能的强大工具。超声波的一种局限性是，它与背景组织之间的对比度低。因此，对一种被称为光声成像的特殊超声进行了广泛的研究。光声成像仅在感兴趣的领域才能产生光。这增加了对比度。不幸的是，光声超声尚未被批准用于人们广泛使用。这可能部分是由于缺乏标准化设备和方法来验证光声成像所需的新型成像设备。因此，这项提出的工作将创建具有已知光学和声学特性的专业塑料对象，适合校准和标准化光声成像设备。该建议结合了学术界和食品药品监督管理局的专业知识，以创建对仪器制造商和医生有用的测试对象和方法。最终的测试对象将提高如何最好地创建光声成像仪器的知识，并可能简化该设备的监管批准。反过来，这将增加患者对这种重要成像技术的机会，以最终提高民族健康和生活质量。技术总结成像提供了类似于超声的深层组织成像，但具有增强的光学对比度以及其他功能和分子成像功能。但是，与成熟技术不同（超声，MRI，CT），没有用于光声成像系统评估的标准化性能测试方法或幻影。基本限制是缺乏在广泛的光波长和声学频率上同时模拟组织特性的材料。这使研究人员，仪器制造商和监管机构没有明确的策略来评估设备安全性和有效性。这项提出的工作将创造具有稳定的，具有生物学相关的成像幻象，并具有良好的光学吸收/散射系数，声学阻抗等，它们在广泛的光波长和声学频率上广泛模拟组织。文献搜索和实验室研究将确定合适的材料，例如聚丙烯酰胺水凝胶或新型聚氯乙烯塑料制剂。固有特性将使用FDA的验证分光光度法和声脉冲传递方法和设备进行测量。一旦对幻影材料的配方进行了优化，我们将以几种特定配置的方式构造幻象，以评估图像质量指标，例如空间分辨率，穿透深度等。然后，这些新型幻影将与三种具有基本不同操作参数范围的光声系统一起使用（例如，光学波长）。将比较设备之间的图像质量指标，以阐明系统之间的性能权衡以及系统设计选择和幻影属性对性能的总体影响。目的是产生具有6个月稳定性的幻影，该幻影范围频谱模仿血红蛋白和脱氧血红蛋白，并包含能够实现图像质量测试的靶标。结果将是一个验证的模拟组织，以支持设备开发人员并为监管决策提供信息，包括用作潜在的FDA医疗设备开发工具。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来支持的。