Improving Weakly Supervised Lesion Segmentation using Multi-Task Learning

International audience; We introduce the concept of multi-task learning to weakly-supervised lesion segmentation, one of the most critical and challenging tasks in medical imaging. Due to the lesions' heterogeneous nature, it is difficult for machine learning models to capture the corresponding variability. We propose to jointly train a lesion segmentation model and a lesion classifier in a multi-task learning fashion, where the supervision of the latter is obtained by clustering the RECIST measurements of the lesions. We evaluate our approach specifically on liver lesion segmentation and more generally on lesion segmentation in computed tomography (CT), as well as segmentation of skin lesions from dermatoscopic images. We show that the proposed joint training improves the quality of the lesion segmentation by 4% percent according to the Dice coefficient and 6% according to averaged Hausdorff distance (AVD), while reducing the training time required by up to 75%.