Privacy-aware deep vein thrombosis segmentation using a multi-model federated learning framework with the federated averaging algorithm.

Deep Vein Thrombosis (DVT) is the formation of blood clots in the deep veins of the calf, requiring precise Computer Tomography (CT) scan segmentation for accurate diagnosis and treatment. We proposed and developed an efficient Federated Learning (FedL) architecture using the Federated Averaging (FedAvg) algorithm. Seven distinct local models were designed and trained on non-independent and identically distributed (Non-IID) CT images to maintain data privacy and security, enhancing DVT segmentation efficiency and accuracy. The global model was progressively improved by aggregating the local model's weights using FedAvg algorithm. Our algorithm was evaluated in three phases using datasets of 1000, 2000, and 3000 samples to assess the global model's performance. Phase 1 involved three clients, each with unique local models (Convolutional Neural Network (CNN), Sequential, and Semantic). While, Phase 2 expanded to five clients, incorporating additional models (U-Net and VGG Net-19). In Phase 3, scaled to seven clients with advanced models (Modified U-Net and Modified-Net). Empirical results across Phases 1-3 showed significant gains with increasing dataset size -attaining higher Accuracy ([Formula: see text]) and F1-score ([Formula: see text]), while Tversky Loss decreased to ([Formula: see text]). Notably, our framework proved consistent improvement across all phases, achieving a reduction in validation loss from 0.910 to 0.061 and a communication cost increase from 14 MB to 3279 MB with increasing model scales. The average training time rose proportionally (7.67 s → 18,702 s) while maintaining robust differential privacy preservation (ε [Formula: see text]) and improved client heterogeneity ([Formula: see text]), demonstrating our framework's scalability and stability across heterogeneous environments.