Sedighin Farnaz, Rezaei Fatemeh, Monemian Maryam
Medical Image and Signal Processing Research Center, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, 8174673461, Iran.
Sci Rep. 2025 Jul 9;15(1):24757. doi: 10.1038/s41598-025-07448-x.
Optical Coherence Tomography Angiography (OCTA) is a non-invasive method for vascular imaging of different tissues. Several diseases can disturb the blood supplying of retinal tissues which leads to loss of blood vessels and a reduction in the vascular density of retinal tissue. This also changes the size and shape of the FAZ (Fovea Avascular Zone) in the retinal OCTA images. Considering this fact, FAZ segmentation and analyzing its shape, can be used for diagnosing of several eye-related diseases. This paper is devoted to propose new methods for accurate segmentation of FAZ from OCTA images. The proposed methods have three steps: first, FAZ localization, for which, two methods have been proposed. The first one used Low-rank Tensor Ring (TR) decomposition of OCTA images and the other one exploited morphological operators. In the second step, the de-noised OCTA image is used for FAZ segmentation exploiting the information of FAZ localization, and in the third step, the resulting segmented FAZ is refined to derive a clean area. To the best of our knowledge, this is the first time of using low-rank TR estimation for FAZ segmentation. Simulation results confirmed the performance of the proposed methods for an accurate FAZ segmentation.
光学相干断层扫描血管造影（OCTA）是一种用于不同组织血管成像的非侵入性方法。几种疾病会干扰视网膜组织的血液供应，导致血管缺失和视网膜组织血管密度降低。这也会改变视网膜OCTA图像中无血管区（FAZ）的大小和形状。考虑到这一事实，FAZ分割及其形状分析可用于诊断多种眼部相关疾病。本文致力于提出从OCTA图像中准确分割FAZ的新方法。所提出的方法有三个步骤：首先是FAZ定位，为此提出了两种方法。第一种方法使用OCTA图像的低秩张量环（TR）分解，另一种方法利用形态学算子。第二步，利用FAZ定位信息，对去噪后的OCTA图像进行FAZ分割，第三步，对分割得到的FAZ进行细化，以得到一个干净的区域。据我们所知，这是首次将低秩TR估计用于FAZ分割。仿真结果证实了所提出方法在准确分割FAZ方面的性能。
