Liu Bin, Harman Michelle, Giattina Susanne, Stamper Debra L, Demakis Charles, Chilek Mark, Raby Stephanie, Brezinski Mark E
Department of Orthopedic Surgery, Brigham and Women's Hospital, Massachusetts, USA.
Appl Opt. 2006 Jun 20;45(18):4464-79. doi: 10.1364/ao.45.004464.
Assessing tissue birefringence with imaging modality polarization-sensitive optical coherence tomography (PS-OCT) could improve the characterization of in vivo tissue pathology. Among the birefringent components, collagen may provide invaluable clinical information because of its alteration in disorders ranging from myocardial infarction to arthritis. But the features required of clinical imaging modality in these areas usually include the ability to assess the parameter of interest rapidly and without extensive data analysis, the characteristics that single-detector PS-OCT demonstrates. But beyond detecting organized collagen, which has been previously demonstrated and confirmed with the appropriate histological techniques, additional information can potentially be gained with PS-OCT, including collagen type, form versus intrinsic birefringence, the collagen angle, and the presence of multiple birefringence materials. In part I, we apply the simple but powerful fast-Fourier transform (FFT) to both PS-OCT mathematical modeling and in vitro bovine meniscus for improved PS-OCT data analysis. The FFT analysis yields, in a rapid, straightforward, and easily interpreted manner, information on the presence of multiple birefringent materials, distinguishing the true anatomical structure from patterns in image resulting from alterations in the polarization state and identifying the tissue/phantom optical axes. Therefore the use of the FFT analysis of PS-OCT data provides information on tissue composition beyond identifying the presence of organized collagen in real time and directly from the image without extensive mathematical manipulation or data analysis. In part II, Helistat phantoms (collagen type I) are analyzed with the ultimate goal of improved tissue characterization. This study, along with the data in part I, advance the insights gained from PS-OCT images beyond simply determining the presence or absence of birefringence.
使用偏振敏感光学相干断层扫描（PS-OCT）成像方式评估组织双折射可以改善对体内组织病理学的特征描述。在双折射成分中，胶原蛋白因其在从心肌梗死到关节炎等各种疾病中的变化，可能提供宝贵的临床信息。但这些领域临床成像方式所需的特征通常包括能够快速评估感兴趣的参数且无需广泛的数据分析，单探测器PS-OCT就具备这些特征。但除了检测先前已用适当组织学技术证实的有序胶原蛋白外，PS-OCT还可能获得其他信息，包括胶原类型、形态与固有双折射、胶原角度以及多种双折射物质的存在情况。在第一部分中，我们将简单但强大的快速傅里叶变换（FFT）应用于PS-OCT数学建模和体外牛半月板，以改进PS-OCT数据分析。FFT分析以快速、直接且易于解释的方式得出有关多种双折射物质存在的信息，将真实解剖结构与因偏振态改变而产生的图像模式区分开来，并确定组织/模型的光轴。因此，对PS-OCT数据进行FFT分析可提供有关组织组成的信息，不仅能实时直接从图像中识别有序胶原蛋白的存在，而无需进行广泛的数学运算或数据分析。在第二部分中，对Helistat模型（I型胶原蛋白）进行了分析，最终目的是改进组织特征描述。这项研究与第一部分的数据一起，深化了从PS-OCT图像中获得的见解，而不仅仅是简单地确定双折射的存在与否。
