Enhancing Cross-Modal Medical Image Segmentation through Compositionality
Aniek Eijpe, Valentina Corbetta, Kalina Chupetlovska, Regina Beets-Tan, Wilson Silva
TL;DR
This work tackles cross-modal medical image segmentation under substantial domain shift between imaging modalities. It introduces compositionality as an inductive bias to learn content representations via learnable von Mises-Fisher kernels, enabling content-style disentanglement and reducing model complexity. The approach combines cross-modal translation with a compositional representation module to produce interpretable, spatially-discriminative features ($Z_{vMF}$) used for segmentation, achieving improved performance on MM-WHS and CHAOS while lowering computational costs. The findings suggest that compositional content representations can enhance generalization across modalities and offer meaningful insights into the segmentation process, with practical impact for multi-modality clinical workflows.
Abstract
Cross-modal medical image segmentation presents a significant challenge, as different imaging modalities produce images with varying resolutions, contrasts, and appearances of anatomical structures. We introduce compositionality as an inductive bias in a cross-modal segmentation network to improve segmentation performance and interpretability while reducing complexity. The proposed network is an end-to-end cross-modal segmentation framework that enforces compositionality on the learned representations using learnable von Mises-Fisher kernels. These kernels facilitate content-style disentanglement in the learned representations, resulting in compositional content representations that are inherently interpretable and effectively disentangle different anatomical structures. The experimental results demonstrate enhanced segmentation performance and reduced computational costs on multiple medical datasets. Additionally, we demonstrate the interpretability of the learned compositional features. Code and checkpoints will be publicly available at: https://github.com/Trustworthy-AI-UU-NKI/Cross-Modal-Segmentation.
