Zhang Yi, Gong Zhaoyu, Shi Yaping, Le Viet Hoan, Pan Hefu, Liu Jian, Wang Ruikang K
Department of Bioengineering, University of Washington, Seattle, WA 98105, USA.
Department of Ophthalmology, University of Washington, Seattle, WA 98109, USA.
Biomed Opt Express. 2025 Jun 16;16(7):2808-2823. doi: 10.1364/BOE.563121. eCollection 2025 Jul 1.
Optical coherence tomography (OCT) generates cross-sectional images by measuring backscattered light from within tissue, with image contrast influenced by tissue optical properties, primarily optical scattering and illumination conditions. The optical attenuation coefficient (OAC), derived from the OCT signal, can decouple illumination effects and directly probe the scattering properties, offering potential functional contrast. However, the existing OAC quantification methods are prone to bias in multilayered structures, such as retinal tissue, primarily due to the inhomogeneity in backscattering fraction. In this study, we introduce a layer-based iterative method that improves OAC accuracy by accounting for layer-specific backscattering fractions. Our approach refines OAC calculations through an optimized depth-resolved framework, iteratively adjusting the residual light term for improved estimation. We validated the method's convergence and accuracy through both mathematical derivation and numerical simulations. Further, we evaluated its clinical applicability in healthy subjects. Comparative results demonstrated that our method enhances tissue characterization, highlighting its potential to advance retinal imaging and disease assessment.
光学相干断层扫描（OCT）通过测量组织内部的背向散射光来生成横截面图像，图像对比度受组织光学特性影响，主要是光学散射和照明条件。从OCT信号得出的光学衰减系数（OAC）可以消除照明影响并直接探测散射特性，提供潜在的功能对比度。然而，现有的OAC量化方法在多层结构（如视网膜组织）中容易产生偏差，主要是由于背向散射分数的不均匀性。在本研究中，我们引入了一种基于层的迭代方法，该方法通过考虑特定层的背向散射分数来提高OAC的准确性。我们的方法通过优化的深度分辨框架改进OAC计算，迭代调整残余光项以改进估计。我们通过数学推导和数值模拟验证了该方法的收敛性和准确性。此外，我们评估了其在健康受试者中的临床适用性。比较结果表明，我们的方法增强了组织表征，突出了其推进视网膜成像和疾病评估的潜力。
