Localized Perturbations For Weakly-Supervised Segmentation of Glioma Brain Tumours

Sajith Rajapaksa; Farzad Khalvati

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arXiv · 2111.14953

Localized Perturbations For Weakly-Supervised Segmentation of Glioma Brain Tumours

Sajith Rajapaksa·Farzad Khalvati

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Abstract

Deep convolutional neural networks (CNNs) have become an essential tool in the medical imaging-based computer-aided diagnostic pipeline. However, training accurate and reliable CNNs requires large fine-grain annotated datasets. To alleviate this, weakly-supervised methods can be used to obtain local information from global labels. This work proposes the use of localized perturbations as a weakly-supervised solution to extract segmentation masks of brain tumours from a pretrained 3D classification model. Furthermore, we propose a novel optimal perturbation method that exploits 3D superpixels to find the most relevant area for a given classification using a U-net architecture. Our method achieved a Dice similarity coefficient (DSC) of 0.44 when compared with expert annotations. When compared against Grad-CAM, our method outperformed both in visualization and localization ability of the tumour region, with Grad-CAM only achieving 0.11 average DSC.

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Sajith Rajapaksa, Farzad Khalvati. 2021-11-29. Localized Perturbations For Weakly-Supervised Segmentation of Glioma Brain Tumours. https://arxiv.org/abs/2111.14953

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