Visual interpretability in 3D brain tumor segmentation network. (June 2021)

• Record Type: Journal Article
• Authors: Saleem, Hira; Shahid, Ahmad Raza; Raza, Basit
• Is Part Of: Computers in biology and medicine. Volume 133(2021)
• Publication Date: 2021-06
• Subjects: Visual interpretability -- Explainable artificial intelligence -- Medical imaging -- Brain tumor segmentation -- Visual explanations; Medicine -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; 610.285
• DOI: 10.1016/j.compbiomed.2021.104410
• Languages: English
• ISSNs: 0010-4825

Abstract

Abstract: Medical image segmentation is a complex yet one of the most essential tasks for diagnostic procedures such as brain tumor detection. Several 3D Convolutional Neural Network (CNN) architectures have achieved remarkable results in brain tumor segmentation. However, due to the black-box nature of CNNs, the integration of such models to make decisions about diagnosis and treatment is high-risk in the domain of healthcare. It is difficult to explain the rationale behind the model's predictions due to the lack of interpretability. Hence, the successful deployment of deep learning models in the medical domain requires accurate as well as transparent predictions. In this paper, we generate 3D visual explanations to analyze the 3D brain tumor segmentation model by extending a post-hoc interpretability technique. We explore the advantages of a gradient-free interpretability approach over gradient-based approaches. Moreover, we interpret the behavior of the segmentation model with respect to the input Magnetic Resonance Imaging (MRI) images and investigate the prediction strategy of the model. We also evaluate the interpretability methodology quantitatively for medical image segmentation tasks. To deduce that our visual explanations do not represent false information, we validate the extended methodology quantitatively. We learn that the information captured by the model is coherent with the domain knowledge of human experts, making it more trustworthy. We use the BraTS-2018 dataset to train the 3D brain tumor segmentation network and perform interpretability experiments to generate visual explanations. Graphical abstract: Image 1 Highlights: Extend CAM based method for interpretability in 3D brain tumor segmentation model. Extract 3D explanations to understand strategy of the model in tumor prediction. Identify the role of each MRI sequence in the segmentation of tumor sub-regions. Identify the failure modes of our network validate the results using dice loss. Validate and evaluate visual explanations quantitatively and qualitatively.