Applications Of Photon Migration To Tissue Tomography

光子迁移在组织断层扫描中的应用

• 批准号: 6541102
• 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/6541102
• 关键词: bioimaging /biomedical imaging; breast neoplasm /cancer diagnosis; breast neoplasms; clinical research; human subject; laboratory mouse; liposomes; noninvasive diagnosis; spectrometry; tomography

Our work on theoretical, experimental, and computational aspects of light -tissue interactions for non-invasive quantitative optical imaging and spectroscopy has been continued. Several new sets of time resolved transillumination of human breast patients have been provided by researchers at PTB in Berlin 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(s) and those of the background(s). Separation of the scattering and absorption properties allowed us to use standard spectroscopic techniques to estimate the oxygen saturation and the total blood volume of the tumor(s) and background tissue(s. Effects of breast edges on measured light intensities have been modeled using the mean time of flight which depends on the distance of the laser source and the boundaries of the breast. 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 used our oblique angle spectroscopic device on seven patients with oral leukoplakia in a double-blinded Phase II clinical trial (designed by NCI) for the study of inflammation and effects of chemopreventative drugs. As the results of the clinical trial will be available. we will compare our finding with results of punch biopsies. This allow us to evaluate the robustness of our method, and refine our theoretical model and the design of our device. 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 Tel-Aviv University we 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. Mice models have been successfully used to assess the robustness of our model. 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、实验和计算方面的工作一直在继续。柏林PTB的研究人员提供了几组新的人类乳房患者的时间分辨透照测量，这些测量是在两个波长(670和780 nm)的乳房图像的透照几何中进行的。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。我们成功地找到了肿瘤的确切位置，估计了肿瘤的大小，并恢复了肿瘤(S)和背景(S)的散射和吸收系数。散射和吸收特性的分离使我们能够使用标准的光谱技术来估计肿瘤(S)和背景组织(S)的血氧饱和度和总血流量。使用平均飞行时间来模拟乳房边缘对测量的光强度的影响，平均飞行时间取决于激光光源和乳房边界的距离。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。我们用我们的斜角光谱仪对7例口腔白斑患者进行了双盲II期临床试验(由NCI设计)，以研究炎症和化学预防药物的作用。因为临床试验的结果将会公布。我们将把我们的发现与穿孔活检的结果进行比较。这使我们能够评估我们方法的稳健性，并改进我们的理论模型和设备的设计。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，我们继续研究我们先前开发的3D重建算法的实际实现，该算法定位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，作为体内局部荧光肿块的模型。小鼠模型已经被成功地用于评估我们模型的稳健性。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。