Frequency Adapter with SAM for Generalized Medical Image Segmentation

2026-05-11Computer Vision and Pattern Recognition

Computer Vision and Pattern Recognition
AI summary

The authors address the problem of medical image segmentation models not working well on new datasets due to differences like scanner types or imaging settings. They propose a new method called FSAM that improves an existing model (SAM) by focusing on frequency information, which helps it better handle these differences. FSAM uses a special tuning technique to efficiently learn important features that remain consistent across domains, leading to better segmentation results on different medical images. Their tests on eye and prostate images show FSAM performs better than previous methods.

Medical Image SegmentationDomain GeneralizationSegment Anything Model (SAM)Frequency DomainLow-Rank Adaptation (LoRA)Deep LearningDomain ShiftFundus ImagingProstate Imaging
Authors
Phuoc-Nguyen Bui, Van-Nguyen Pham, Duc-Tai Le, Junghyun Bum, Hyunseung Choo
Abstract
Medical image segmentation is a critical task in computer-aided diagnosis and treatment planning. However, deep learning models often struggle to generalize across datasets due to domain shifts arising from variations in imaging protocols, scanner types, and patient populations. Traditional domain generalization (DG) methods utilize causal feature learning, adversarial consistency, and style augmentation to improve segmentation robustness. While effective, these approaches rely on explicit feature alignment, adversarial objectives, or handcrafted augmentations, which may not fully exploit the capabilities of foundation models. Recently, the Segment Anything Model (SAM) has demonstrated strong generalization capabilities in segmentation tasks. SAM-based DG methods attempt to improve medical image segmentation. However, these approaches primarily operate in the spatial domain and overlook frequency-based discrepancies that significantly affect model robustness. In this work, we propose Frequency-based Domain Generalization with SAM (FSAM), a novel framework that integrates Low-Rank Adaptation (LoRA) for efficient fine-tuning and a frequency adapter to incorporate frequency-domain representations for single-source domain generalization. FSAM enhances SAM's segmentation robustness by extracting domain-invariant high-frequency features, mitigating frequency-related domain shifts. Experimental results on fundus and prostate datasets demonstrate that FSAM outperforms existing traditional DG and SAM-based DG approaches in domain generalization. Codes and pre-trained models will be made available on GitHub.