Cameron Andrew, Lui Dorothy, Boroomand Ameneh, Glaister Jeffrey, Wong Alexander, Bizheva Kostadinka
Department of Systems Design Engineering, University of Waterloo, 200 University Avenue W, Waterloo, ON, N2T 3G1, Canada.
Biomed Opt Express. 2013 Aug 28;4(9):1769-85. doi: 10.1364/BOE.4.001769. eCollection 2013.
Optical coherence tomography (OCT) allows for non-invasive 3D visualization of biological tissue at cellular level resolution. Often hindered by speckle noise, the visualization of important biological tissue details in OCT that can aid disease diagnosis can be improved by speckle noise compensation. A challenge with handling speckle noise is its inherent non-stationary nature, where the underlying noise characteristics vary with the spatial location. In this study, an innovative speckle noise compensation method is presented for handling the non-stationary traits of speckle noise in OCT imagery. The proposed approach centers on a non-stationary spline-based speckle noise modeling strategy to characterize the speckle noise. The novel method was applied to ultra high-resolution OCT (UHROCT) images of the human retina and corneo-scleral limbus acquired in-vivo that vary in tissue structure and optical properties. Test results showed improved performance of the proposed novel algorithm compared to a number of previously published speckle noise compensation approaches in terms of higher signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and better overall visual assessment.
光学相干断层扫描（OCT）能够在细胞水平分辨率下对生物组织进行非侵入性三维可视化。OCT中重要的生物组织细节可视化常常受到散斑噪声的阻碍，而散斑噪声补偿可以改善这些有助于疾病诊断的细节的可视化效果。处理散斑噪声的一个挑战在于其固有的非平稳特性，即潜在的噪声特征会随空间位置而变化。在本研究中，提出了一种创新的散斑噪声补偿方法，用于处理OCT图像中散斑噪声的非平稳特性。所提出的方法以基于非平稳样条的散斑噪声建模策略为核心，以表征散斑噪声。该新方法应用于体内获取的人视网膜和角膜缘的超高分辨率OCT（UHROCT）图像，这些图像在组织结构和光学特性方面存在差异。测试结果表明，与许多先前发表的散斑噪声补偿方法相比，所提出的新算法在更高的信噪比（SNR）、对比度噪声比（CNR）以及更好的整体视觉评估方面具有更好的性能。
