@inproceedings{PB-VRVis-2020-026, author = {Neubauer, Theresa and Wimmer, Maria and Berg, Astrid and Major, David and Lenis, Dimitrios and Beyer, Thomas and Saponjski, Jelena and B{\"u}hler, Katja}, title = {Soft Tissue Sarcoma Co-Segmentation in Combined MRI and PET/CT Data}, year = {2020}, booktitle = {"Multimodal Learning for Clinical Decision Support" Workshop of the International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) 2020}, editor = {Syeda-Mahmood T. et al.}, doi = {https://doi.org/10.1007/978-3-030-60946-7_10}, url = {https://www.vrvis.at/publications/PB-VRVis-2020-026}, publisher = {Springer, Cham}, isbn = {978-3-030-60945-0}, pages = {97-105}, volume = {12445}, abstract = {Tumor segmentation in multimodal medical images has seen a growing trend towards deep learning based methods. Typically, studies dealing with this topic fuse multimodal image data to improve the tumor segmentation contour for a single imaging modality. However, they do not take into account that tumor characteristics are emphasized differently by each modality, which affects the tumor delineation. Thus, the tumor segmentation is modality- and task-dependent. This is especially the case for soft tissue sarcomas, where, due to necrotic tumor tissue, the segmentation differs vastly. Closing this gap, we develop a modalityspecific sarcoma segmentation model that utilizes multimodal image data to improve the tumor delineation on each individual modality. We propose a simultaneous co-segmentation method, which enables multimodal feature learning through modality-specific encoder and decoder branches, and the use of resource-efficient densely connected convolutional layers. We further conduct experiments to analyze how different input modalities and encoder-decoder fusion strategies affect the segmentation result. We demonstrate the effectiveness of our approach on public soft tissue sarcoma data, which comprises MRI (T1 and T2 sequence) and PET/CT scans. The results show that our multimodal co-segmentation model provides better modality-specific tumor segmentation than models using only the PET or MRI (T1 and T2) scan as input.}, keywords = {Tumor Co-segmentation; Multimodality; Deep Learning}, }