Tan Bingyao, Wong Damon W K, Yow Ai Ping, Yao Xinwen, Schmetterer Leopold
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:1883-1886. doi: 10.1109/EMBC44109.2020.9175242.
Precise three-dimensional segmentation of choroidal vessels helps us understand the development and progression of multiple ocular diseases, such as agerelated macular degeneration and pathological myopia. Here we propose a novel automatic choroidal vessel segmentation framework for swept source optical coherence tomography (SS-OCT) to visualize and quantify three-dimensional choroidal vessel networks. Retinal pigment epithelium (RPE) was delineated from volumetric data and enface frames along the depth were extracted under the RPE. Choroidal vessels on the first enface frame were labeled by adaptive thresholding and each subsequent frame was segmented via segment propagation from the frame above and was in turn used as the reference for the next frame. Choroid boundary was determined by structural similarity index between adjacent frames. The framework was tested on 33 mm SS-OCT volumes acquired by a prototype SS-OCT system (PlexElite 9000, Zeiss Meditec, Dublin, CA, US), and vessel metrics including perfusion density, vessel density and mean vessel diameter were computed. Results from human subjects (N = 8) and non-human primates (N = 6) were summarized.Clinical Relevance- Accurate 3D choroid vessel segmentation can help clinicians better quantify blood perfusion which can lead to improved diagnosis and management of retinal eye diseases.
脉络膜血管的精确三维分割有助于我们了解多种眼部疾病的发展和进展，如年龄相关性黄斑变性和病理性近视。在此，我们提出了一种用于扫频源光学相干断层扫描（SS-OCT）的新型自动脉络膜血管分割框架，以可视化和量化三维脉络膜血管网络。从体积数据中勾勒出视网膜色素上皮（RPE），并在RPE下方提取沿深度的正面图像帧。通过自适应阈值法对第一帧正面图像上的脉络膜血管进行标记，随后的每一帧通过从上方帧进行分割传播来进行分割，并依次用作下一帧的参考。通过相邻帧之间的结构相似性指数确定脉络膜边界。该框架在由原型SS-OCT系统（PlexElite 9000，蔡司医疗技术公司，美国加利福尼亚州都柏林）采集的3×3 mm SS-OCT体积数据上进行了测试，并计算了包括灌注密度、血管密度和平均血管直径在内的血管指标。总结了人类受试者（N = 8）和非人灵长类动物（N = 6）的结果。临床相关性——准确的三维脉络膜血管分割可以帮助临床医生更好地量化血液灌注，从而改善视网膜眼部疾病的诊断和管理。
