Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, USA.
Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA.
Sci Rep. 2021 Aug 4;11(1):15826. doi: 10.1038/s41598-021-95219-9.
Quantitative imaging using optical coherence tomography angiography (OCTA) could provide objective tools for the detection and characterization of diabetic retinopathy (DR). In this study, an operator combining the second derivative and Gaussian multiscale convolution is applied to identify the retinal orientation at each pixel in the OCTA image. We quantified the pattern of retinal vascular orientation and developed three novel quantitative metrics including vessel preferred orientation, vessel anisotropy, and vessel area. Each of eight 45º sectors of the circular disk centered at the macular region was defined as the region of interest. Significant sectoral differences were observed in the preferred orientation (p < 0.0001) and vessel area (p < 0.0001) in the 34 healthy subjects, whereas vessel anisotropy did not demonstrate a significant difference among the eight sectors (p = 0.054). Differential retinal microvascular orientation patterns were observed between healthy controls (n = 34) and the DR subjects (n = 7). The vessel area characterized from the vascular orientation pattern was shown to be strongly correlated with the traditionally reported vessel density (Pearson R > 0.97, p < 0.0001). With three metrics calculated from the vascular orientation pattern simultaneously and sectorally, our quantitative assessment for retinal microvasculature provides more information than vessel density alone and thereby may enhance the detection of DR. These preliminary results suggest the feasibility and advantage of our vessel orientation-based quantitative approach using OCTA to characterize DR-associated changes in retinal microvasculature.
使用光学相干断层扫描血管造影术（OCTA）进行定量成像，可以为糖尿病视网膜病变（DR）的检测和特征提供客观工具。在这项研究中，应用了一种将二阶导数和高斯多尺度卷积相结合的算子，以确定 OCTA 图像中每个像素的视网膜方向。我们量化了视网膜血管方向的模式，并开发了三种新的定量指标，包括血管优势方向、血管各向异性和血管面积。以黄斑区为中心的圆形磁盘的每八个 45°扇区都被定义为感兴趣区域。在 34 名健康受试者中，观察到优势方向（p<0.0001）和血管面积（p<0.0001）在各个扇区之间存在显著差异，而血管各向异性在八个扇区之间没有显著差异（p=0.054）。在健康对照组（n=34）和 DR 组（n=7）之间观察到了不同的视网膜微血管方向模式。从血管方向模式中得出的血管面积与传统报道的血管密度具有很强的相关性（Pearson R>0.97，p<0.0001）。通过同时和分扇区计算三个来自血管方向模式的指标，我们对视网膜微血管的定量评估提供的信息比仅血管密度更多，从而可能增强对 DR 的检测。这些初步结果表明，使用 OCTA 基于血管方向的定量方法来描述与 DR 相关的视网膜微血管变化具有可行性和优势。
