Distribution-aware Fairness Learning in Medical Image Segmentation From A Control-Theoretic Perspective
Yujin Oh, Pengfei Jin, Sangjoon Park, Sekeun Kim, Siyeop Yoon, Kyungsang Kim, Jin Sung Kim, Xiang Li, Quanzheng Li
TL;DR
The paper tackles fairness in medical image segmentation under distributional biases across demographic and clinical factors. It proposes Distribution-aware Mixture of Experts ($dMoE$), a control-inspired MoE that incorporates distribution information into gating to enable adaptive, attribute-aware parameter selection across Transformer and CNN backbones for 2D and 3D tasks. The approach is theoretically framed within optimal-control and mode-switching concepts and validated on Harvard-FairSeg, HAM10000, and a radiotherapy target dataset, showing state-of-the-art fairness metrics and robust generalization, with extensive ablations. The work advances fairness in clinical AI by bridging control theory and distribution-aware learning, providing a practical, transferable framework and releasing source code for reproducibility and further deployment in diverse hospital settings.
Abstract
Ensuring fairness in medical image segmentation is critical due to biases in imbalanced clinical data acquisition caused by demographic attributes (e.g., age, sex, race) and clinical factors (e.g., disease severity). To address these challenges, we introduce Distribution-aware Mixture of Experts (dMoE), inspired by optimal control theory. We provide a comprehensive analysis of its underlying mechanisms and clarify dMoE's role in adapting to heterogeneous distributions in medical image segmentation. Furthermore, we integrate dMoE into multiple network architectures, demonstrating its broad applicability across diverse medical image analysis tasks. By incorporating demographic and clinical factors, dMoE achieves state-of-the-art performance on two 2D benchmark datasets and a 3D in-house dataset. Our results highlight the effectiveness of dMoE in mitigating biases from imbalanced distributions, offering a promising approach to bridging control theory and medical image segmentation within fairness learning paradigms. The source code will be made available. The source code is available at https://github.com/tvseg/dMoE.
