Artifact-suppressed 3D retinal microvascular segmentation via multi-scale topology regulation.

Optical coherence tomography angiography (OCTA) enables non-invasive visualization of retinal microvasculature, and accurate 3D vessel segmentation is essential for quantifying biomarkers critical for early diagnosis and monitoring of diabetic retinopathy. However, reliable 3D OCTA segmentation is hindered by capillary invisibility, complex vascular topology, and motion artifacts, which compromise biomarker accuracy. Furthermore, the scarcity of manually annotated 3D OCTA microvascular data constrains methodological development. To address this challenge, we introduce our publicly accessible 3D microvascular dataset and propose MT-Net, a multi-view, topology-aware 3D retinal microvascular segmentation network. First, a novel dimension transformation strategy is employed to enhance topological accuracy by effectively encoding spatial dependencies across multiple planes. Second, to mitigate the impact of motion artifacts, we introduce a unidirectional Artifact Suppression Module (ASM) that selectively suppresses noise along the B-scan direction. Third, a Twin-Cross Attention Module (TCAM), guided by vessel centerlines, is designed to enhance the continuity and completeness of segmented vessels by reinforcing cross-view contextual information. Experiments on two 3D OCTA datasets show that MT-Net achieves state-of-the-art accuracy and topological consistency, with strong generalizability validated by cross-dataset analysis. We plan to release our manual annotations to facilitate future research in retinal OCTA segmentation.