🤖 AI Summary
Pathological image registration suffers from disrupted spatial correspondence and deformation distortion caused by lesions, compounded by the absence of pixel-level annotations and anatomical consistency constraints. To address these challenges, we propose the first unsupervised co-learning framework explicitly designed for lesion robustness. Our method establishes bidirectional semantic constraints between registration and semantic segmentation tasks to jointly model anatomical consistency and align domain-invariant features. It employs a deformable convolutional U-Net for registration, a contrastive learning–driven segmentation branch, and a composite loss integrating mutual information maximization and deformation regularization. Evaluated on the BraTS and PANDA datasets, our approach achieves a 12.6% improvement in registration accuracy and a Dice score of 0.84—substantially outperforming state-of-the-art unsupervised methods. This work advances pathological image registration by unifying structural fidelity, lesion-invariant feature learning, and geometric regularization within a single, annotation-free framework.