A Random Feature Augmentation for Domain Generalization in Medical Image Segmentation

Deep convolutional neural networks (DCNNs) significantly improve the performance of medical image segmentation. Nevertheless, medical images frequently experience distribution discrepancies, which fails to maintain their robustness when applying trained models to unseen clinical data. To address this problem, domain generalization methods were proposed to enhance the generalization ability of DCNNs. Feature space-based data augmentation methods have proven their effectiveness to improve domain generalization. However, existing methods still mainly rely on certain prior knowledge or assumption, which has limitations in enriching the diversity of source domain data. In this paper, we propose a random feature augmentation (RFA) method to diversify source domain data at the feature level without prior knowledge. Specifically, we explore the effectiveness of random convolution at the feature level for the first time and prove experimentallyt hat itc an adequately preserve domain-invariant information while perturbing domainspecific information. Furthermore, tocapture the same domain-invariant information from the augmented features of RFA, we present a domain-invariant consistent learning strategy to enable DCNNs to learn a more generalized representation. Our proposed method achieves state-of-the-art performance on two medical image segmentation tasks, including optic cup/disc segmentation on fundus images and prostate segmentation on MRI images.