Accurate medical image segmentation commonly requires effective learning of the complementary information from multimodal data. However, in clinical practice, we often encounter the problem of missing imaging modalities. We tackle this challenge and propose a novel multimodal segmentation framework which is robust to the absence of imaging modalities. Our network uses feature disentanglement to decompose the input modalities into the modality-specific appearance code, which uniquely sticks to each modality, and the modality-invariant content code, which absorbs multimodal information for the segmentation task. With enhanced modality-invariance, the disentangled content code from each modality is fused into a shared representation which gains robustness to missing data. The fusion is achieved via a learning-based strategy to gate the contribution of different modalities at different locations. We validate our method on the important yet challenging multimodal brain tumor segmentation task with the BRATS challenge dataset. With competitive performance to the state-of-the-art approaches for full modality, our method achieves outstanding robustness under various missing modality(ies) situations, significantly exceeding the state-of-the-art method by over 16% in average for Dice on whole tumor segmentation.

本研究提出一种新的多模态分割框架，使用特征解缠来将多模态数据分解为特定于每种模态的出现代码和吸收多模态信息的模态不变内容代码，从而通过在不同区域门控不同模态的贡献来融合来自每种模态的解缠内容代码，在各个模态数据缺失的情况下获得了优异的鲁棒性，尤其是在BRATS挑战数据集的脑肿瘤分割任务中表现出了优秀的性能。

基于特征分离和门控融合的鲁棒多模式脑肿瘤分割