DS-WaveGNN: a Dual-path wavelet graph neural network for fundus image classification
摘要
Automated diabetic retinopathy (DR) screening must capture both global retinal topology and fine-grained pathological details, which is difficult for standard grid-based Convolutional Neural Networks (CNNs). We propose DS-WaveGNN, a dual-path wavelet graph neural network. After contrast enhancement and superpixel segmentation, DS-WaveGNN builds a spatio-semantic graph that explicitly fuses deep semantic features with clinical-pathological priors, such as texture and microvascular density. An adaptive wavelet mechanism dynamically decouples the graph signal into low- and high-frequency paths, separating macroscopic vascular structures from microscopic lesion details. These paths are processed independently using lightweight Deep Separable Graph Convolutions (DSGraphConv), and an ordinal-aware hybrid loss penalizes large-span severity errors. On APTOS 2019, DS-WaveGNN achieves 86.01% accuracy and 0.9122 Quadratic Weighted Kappa (QWK) for five-class grading, and 99.56% accuracy for binary screening. After retraining on Messidor-2 with the same protocol, it achieves 80.25% accuracy and 0.8460 QWK, demonstrating robust multiscale graph representation for DR grading.