M$^{2}$SegMamba: Mamba-Based Incomplete Multimodal Learning for Brain Tumor Segmentation With Few Samples

The accurate segmentation of brain tumors plays an important role in clinical diagnosis and treatment. Multimodal magnetic resonance imaging (MRI) can provide rich and complementary information for accurate brain tumor segmentation. However, the common problems of incomplete modalities and small samples in clinical practice seriously affect the performance of multimodal segmentation. In this work, we design a new framework, named M$^{2}$SegMamba, using Mamba and Masked Autoencoder networks for both supervised and self-supervised learning, aimed at handling small sample brain tumor segmentation under various incomplete multimodality settings. We construct a masking strategy suitable for multimodal brain tumors to precisely extract image features, which serves as the foundation for image segmentation. By fully leveraging the capabilities of the Mamba network, we design a multi-traversal method to facilitate the interaction between inter-modal and cross-modal image features. Meanwhile, the introduction of TSmamba in skipping connections efficiently integrates multimodal features. Auxiliary regularizers are introduced in both the encoder and decoder to further enhance the model's robustness to incomplete modalities. We conducted experiments on the BraTS 2018 and BraTS 2020 datasets, and the results demonstrate that our method outperforms state-of-the-art brain tumor segmentation methods on most subsets of missing modalities.