Applications of Photon Migration to Tissue Tomography and Spectroscopy

光子迁移在组织断层扫描和光谱学中的应用

• 批准号: 6432508
• 负责人: Amir H Gandjbakhche
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6432508
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; fluorescent dye /probe; mathematical model; model design /development; nephelometry; noninvasive diagnosis; optics; phantom model; structural biology; time resolved data; tomography

We have continued our work on theoretical, experimental, and computational aspects of light -tissue interactions for non-invasive quantitative optical imaging and spectroscopy. Researchers at PTB of Berlin provided us time of flight measurements in transillumination geometry of breast images in two wavelengths (670 and 780nm). We have applied our methodology known as time-dependent contrast functions, to quantify the size and the optical properties of the normal tissue background and those of the tumor localized by standard mammography. We were successfully able to find the exact location, estimate the size, and retrieve the scattering and the absorption coefficients of the tumor and those of the background. Using the absorption spectra of oxy- and deoxy-hemoglobin, we were able to estimate the oxygen saturation and the total blood volume of the tumor and background tissue from the absorption coefficients at 670 and 780nm. Work is underway to study the effects of boundaries on the images. In order to avoid incisional biopsy in the oral cavity, a theoretical framework has been developed to quantify the thickening of the epithelial layer in oral mucosa non-invasively. We have developed a spectroscopic device which uses an oblique angle reflectance setting and started to be used in a Phase II clinical trial (designed by NCI) for the non-invasive study of inflammation and effects of chemopreventative drugs. The results from a patient with leukoplakia compared to that obtained from a normal subject show qualitatively the prediction of the theory. Work is underway to screen more patients and make the measurement more quantitative.We are pursuing the use of exogenous and endogenous fluorescent markers to be able to achieve specificity of the spectroscopic signatures of the tissue abnormality under investigation. In collaboration with the University of Tel-Aviv, we have been awarded a BSF grant to continue our research on practical implementation of our previously developed 3D reconstruction algorithm which localizes the position and the concentration of fluorophore masses. Our inverse algorithm will be used to find the position and the concentration of liposomes filled with fluorescent particles as a model for localized fluorescent masses in vivo.. Along these line of research, we are testing an analytical theory of photon migration to retrieve the life-time of biological analytes by using phantom experiments. We are continuing a collaboration with researchers at NCI to study the practical use of our photon migration theory in the development of a guided biopsy infrared fluorescence imaging system for sentinel node detection in breast cancer using fluorescent particles.

我们继续在非侵入性定量光学成像和光谱学的光-组织相互作用的理论、实验和计算方面进行工作。柏林PTB的研究人员为我们提供了两种波长(670和780 nm)的乳房图像的透光几何飞行时间测量。我们应用了我们的方法，称为时间依赖对比函数，以量化正常组织背景的大小和光学性质，以及通过标准乳房X光摄影定位的肿瘤的大小和光学性质。我们成功地找到了准确的位置，估计了肿瘤的大小，并恢复了肿瘤和背景的散射和吸收系数。利用氧合和脱氧血红蛋白的吸收光谱，我们能够从670和780 nm的吸收系数估计出肿瘤和背景组织的血氧饱和度和总血容量。研究边界对图像的影响的工作正在进行中。为了避免口腔切开活检，人们发展了一个理论框架来非侵入性地量化口腔黏膜上皮层的增厚。我们已经开发了一种使用斜角反射设置的光谱设备，并开始用于第二阶段临床试验(由NCI设计)，用于非侵入性研究炎症和化学预防药物的效果。白斑患者的结果与正常人的结果相比，定性地表明了该理论的预测。目前正在对更多的患者进行筛查，并使测量更加量化。我们正在寻求使用外源性和内源性荧光标记物，以实现被调查组织异常的光谱特征的特异性。与特拉维夫大学合作，我们获得了BSF的资助，继续研究我们之前开发的3D重建算法的实际实施，该算法定位了荧光团的位置和浓度。我们的逆算法将被用来寻找充满荧光颗粒的脂质体的位置和浓度，作为体内局部荧光团块的模型。沿着这些研究路线，我们正在测试光子迁移的分析理论，通过使用模体实验来恢复生物分析物的寿命。我们正在继续与NCI的研究人员合作，研究我们的光子迁移理论在开发利用荧光颗粒检测乳腺癌前哨淋巴结的引导活检红外荧光成像系统中的实际应用。