Bidirectional Channel-selective Semantic Interaction for Semi-Supervised Medical Segmentation
Kaiwen Huang, Yizhe Zhang, Yi Zhou, Tianyang Xu, Tao Zhou
TL;DR
The paper tackles semi-supervised medical image segmentation under limited annotations by introducing BCSI, a single-model framework that enables bidirectional cross-stream interaction between labeled and unlabeled data. It combines Semantic-Spatial Perturbation with a learnable Channel-selective Router and Bidirectional Channel-wise Interaction to selectively exchange information on informative channels, guided by a weak-to-strong consistency regime. Empirical results across Left Atrium, BraTS-2019, and Pancreas-CT demonstrate that BCSI outperforms existing methods on Dice, IoU, and boundary metrics, especially at low label ratios. This approach reduces noise and model complexity while delivering robust segmentation performance in 3D medical imaging settings.
Abstract
Semi-supervised medical image segmentation is an effective method for addressing scenarios with limited labeled data. Existing methods mainly rely on frameworks such as mean teacher and dual-stream consistency learning. These approaches often face issues like error accumulation and model structural complexity, while also neglecting the interaction between labeled and unlabeled data streams. To overcome these challenges, we propose a Bidirectional Channel-selective Semantic Interaction~(BCSI) framework for semi-supervised medical image segmentation. First, we propose a Semantic-Spatial Perturbation~(SSP) mechanism, which disturbs the data using two strong augmentation operations and leverages unsupervised learning with pseudo-labels from weak augmentations. Additionally, we employ consistency on the predictions from the two strong augmentations to further improve model stability and robustness. Second, to reduce noise during the interaction between labeled and unlabeled data, we propose a Channel-selective Router~(CR) component, which dynamically selects the most relevant channels for information exchange. This mechanism ensures that only highly relevant features are activated, minimizing unnecessary interference. Finally, the Bidirectional Channel-wise Interaction~(BCI) strategy is employed to supplement additional semantic information and enhance the representation of important channels. Experimental results on multiple benchmarking 3D medical datasets demonstrate that the proposed method outperforms existing semi-supervised approaches.
