Applications Of Photon Migration To Tissue Tomography

我们的工作的理论，实验和计算方面的光组织相互作用的非侵入性定量光学成像和光谱一直在继续。柏林PTB的研究人员提供了几组新的时间分辨透照的人类乳腺患者，在两个波长（670和780 nm）的乳腺图像的透照几何的飞行时间测量。我们已经应用我们的方法，称为时间依赖性对比度函数，量化的大小和光学特性的正常组织背景和肿瘤定位的标准乳房X线摄影。我们成功地找到了准确的位置，估计了大小，并检索了肿瘤和背景的散射和吸收系数。散射和吸收特性的分离允许我们使用标准光谱技术来估计肿瘤和背景组织的氧饱和度和总血容量。乳房边缘对测量的光强度的影响已经使用平均飞行时间来建模，该平均飞行时间取决于激光源的距离和乳房的边界。为了避免在口腔中的切开活检，已经开发了一个理论框架来非侵入性地量化口腔粘膜中的上皮层的增厚。我们已经使用我们的斜角光谱设备在双盲II期临床试验（由NCI设计）的炎症和化学预防药物的影响的研究7例口腔白斑。因为临床试验的结果将会公布。我们将把我们的发现与穿刺活检的结果进行比较。这使我们能够评估我们的方法的鲁棒性，并完善我们的理论模型和我们的设备的设计。我们正在寻求使用外源性和内源性荧光标记物，以便能够实现所研究的组织异常的光谱特征的特异性。与特拉维夫大学合作，我们继续研究我们以前开发的3D重建算法的实际实施，该算法定位荧光团质量的位置和浓度。我们的逆算法将被用来找到的位置和浓度的脂质体填充的荧光颗粒作为一个模型的局部荧光质量在体内。小鼠模型已成功用于评估我们的模型的鲁棒性。沿着这些研究路线，我们正在测试的光子迁移的分析理论，以恢复生物分析物的寿命，通过使用幻影实验。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引导活检红外荧光成像系统中的实际应用，该系统用于使用荧光颗粒进行乳腺癌前哨淋巴结检测。

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.