Yang Bin, Lesicko John, Sharma Manu, Hill Michael, Sacks Michael S, Tunnell James W
Biophotonics Laboratory, Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
Center for Cardiovascular Simulation, Institute for Computational Sciences and Engineering and the Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
Biomed Opt Express. 2015 Mar 31;6(4):1520-33. doi: 10.1364/BOE.6.001520. eCollection 2015 Apr 1.
The measurement of soft tissue fiber orientation is fundamental to pathophysiology and biomechanical function in a multitude of biomedical applications. However, many existing techniques for quantifying fiber structure rely on transmitted light, limiting general applicability and often requiring tissue processing. Herein, we present a novel wide-field reflectance-based imaging modality, which combines polarized light imaging (PLI) and spatial frequency domain imaging (SFDI) to rapidly quantify preferred fiber orientation on soft collagenous tissues. PLI utilizes the polarization dependent scattering property of fibers to determine preferred fiber orientation; SFDI imaging at high spatial frequency is introduced to reject the highly diffuse photons and to control imaging depth. As a result, photons scattered from the superficial layer of a multi-layered sample are highlighted. Thus, fiber orientation quantification can be achieved for the superficial layer with optical sectioning. We demonstrated on aortic heart valve leaflet that, at spatial frequency of f = 1mm(-1) , the diffuse background can be effectively rejected and the imaging depth can be limited, thus improving quantification accuracy.
软组织纤维取向的测量对于众多生物医学应用中的病理生理学和生物力学功能至关重要。然而，许多现有的量化纤维结构的技术依赖于透射光，这限制了其普遍适用性，并且通常需要对组织进行处理。在此，我们提出了一种基于宽场反射的新型成像方式，它结合了偏振光成像（PLI）和空间频域成像（SFDI），以快速量化软胶原组织上的优选纤维取向。PLI利用纤维的偏振依赖性散射特性来确定优选纤维取向；引入高空间频率的SFDI成像以排除高度漫射的光子并控制成像深度。结果，多层样品表层散射的光子被突出显示。因此，通过光学切片可以实现表层纤维取向的量化。我们在主动脉心脏瓣膜小叶上证明，在空间频率f = 1mm(-1) 时，可以有效排除漫射背景并限制成像深度，从而提高量化精度。
