Jørgensen Thomas Martini, Thomadsen Jakob, Christensen Ulrik, Soliman Wael, Sander Birgit
Technical University of Denmark, Riso National Laboratory, Optics and Plasma Research Department, Roskilde, Denmark.
J Biomed Opt. 2007 Jul-Aug;12(4):041208. doi: 10.1117/1.2772879.
Optical coherence tomography (OCT) has already proven an important clinical tool for imaging and diagnosing retinal diseases. Concerning the standard commercial ophthalmic OCT systems, speckle noise is a limiting factor with respect to resolving relevant retinal features. We demonstrate successful suppression of speckle noise from mutually aligning a series of in vivo OCT recordings obtained from the same retinal target using the Stratus system from Humphrey-Zeiss. Our registration technique is able to account for the axial movements experienced during recording as well as small transverse movements of the scan line from one scan to the next. The algorithm is based on a regularized shortest path formulation for a directed graph on a map formed by interimage (B-scan) correlations. The resulting image enhancement typically increases the contrast-to-noise ratio (CNR) with a factor of three or more and facilitates segmentation and quantitative characterization of pathologies. The method is currently successfully being applied by medical doctors in a number of specific retinal case studies.
光学相干断层扫描（OCT）已被证明是用于视网膜疾病成像和诊断的重要临床工具。对于标准的商用眼科OCT系统，散斑噪声是解析相关视网膜特征的限制因素。我们展示了通过使用Humphrey-Zeiss公司的Stratus系统，将从同一视网膜目标获取的一系列体内OCT记录相互对齐，成功抑制了散斑噪声。我们的配准技术能够考虑记录过程中经历的轴向运动以及扫描线从一次扫描到下一次扫描的小横向运动。该算法基于由图像间（B扫描）相关性形成的地图上有向图的正则化最短路径公式。由此产生的图像增强通常会使对比度噪声比（CNR）提高三倍或更多，并有助于病变的分割和定量表征。目前，该方法已在多个特定视网膜病例研究中成功应用于医生。
