University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, Britis, Canada.
Simon Fraser University, School of Engineering Science, Burnaby, British Columbia, Canada.
J Biomed Opt. 2019 Mar;24(3):1-14. doi: 10.1117/1.JBO.24.3.036006.
A segmentation method based on phase retardation measurements from polarization-sensitive optical coherence tomography (PS-OCT) is developed to differentiate the structural zones of articular cartilage. The organization of collagen matrix in articular cartilage varies over the different structural zones, generating different tissue birefringence. Analyzing the slope of the accumulated phase retardation at different depths can detect the variation in tissue birefringence and be used to segment the structural zones. The method is validated on phantoms composed of layers of different materials. Articular cartilage samples from adult swine are segmented with the method. The characteristics in each segmented zone are also examined by histology and high-resolution second-harmonic generation imaging, showing distinctive properties that match with the anatomical structure of articular cartilage. The segmentation algorithm is also applied on PS-OCT images acquired at multiple illumination angles, where the angular dependence of tissue birefringence in the deep zone is detected. This method offers a noninvasive imaging approach to differentiating the structural zones of articular cartilage, as well as a quantification approach based on the phase retardation measurements of PS-OCT. This method has great potential in studying depth-related progression of cartilage degeneration.
一种基于偏振敏感光相干断层扫描（PS-OCT）相位延迟测量的分割方法被开发出来，以区分关节软骨的结构区域。关节软骨中的胶原基质组织在不同的结构区域中排列不同，产生不同的组织双折射。分析不同深度处累积相位延迟的斜率可以检测组织双折射的变化，并用于分割结构区域。该方法在由不同材料层组成的体模上进行了验证。用该方法对来自成年猪的关节软骨样本进行了分割。还通过组织学和高分辨率二次谐波产生成像检查了每个分割区域的特征，显示出与关节软骨解剖结构相匹配的独特特性。该分割算法也应用于在多个照明角度采集的 PS-OCT 图像中，检测到深层区域中组织双折射的角度依赖性。该方法为区分关节软骨的结构区域提供了一种非侵入性的成像方法，以及一种基于 PS-OCT 相位延迟测量的定量方法。该方法在研究软骨退变的深度相关进展方面具有很大的潜力。
