Federated Medical Image Analysis with Virtual Sample Synthesis

Hospitals and research institutions may not be willing to share their collected medical data due to privacy concerns, transmission cost, and the intrinsic value of the data. Federated medical image analysis is thus explored to obtain a global model without access to the images distributed on isolated clients. However, in real-world applications, the local data from each client are likely non-i.i.d distributed because of the variations in geographic factors, patient demographics, data collection process, and so on. Such heterogeneity in data poses severe challenges to the performance of federated learning. In this paper, we introduce federated medical image analysis with virtual sample synthesis (FedVSS). Our method can improve the generalization ability by adversarially synthesizing virtual training samples with the local models and also learn to align the local models by synthesizing high-confidence samples with regard to the global model. All synthesized data will be further utilized in local model updating. We conduct comprehensive experiments on five medical image datasets retrieved from MedMNIST and Camelyon17, and the experimental results validate the effectiveness of our method. Our code is available at Link.