Multi-task learning for classification, segmentation, reconstruction, and detection on chest CT scans
Weronika Hryniewska-Guzik, Maria Kędzierska, Przemysław Biecek
TL;DR
The paper addresses the challenge of identifying lesions on chest CT scans for lung cancer and COVID-19 by proposing a four-task multi-task framework that jointly handles classification, segmentation, reconstruction, and detection. It builds a U-net–based model with a shared encoder and four task-specific decoders, including a Mask-RCNN detection head, and trains with a joint loss $\mathcal{L}_{total}= w_1\cdot \mathcal{L}_{classif}+ w_2\cdot \mathcal{L}_{segm}+ w_3\cdot \mathcal{L}_{recon}+ w_4\cdot \mathcal{L}_{detect}$ where $w_i \in \{0,1\}$; segmentation uses generalized Dice loss. The study uses 2D CT slices from public datasets, tests two backbones, and reports that auxiliary tasks can improve classification and segmentation while detection remains data-limited, highlighting the need for more annotated data and augmentation. Overall, the work demonstrates feasibility of adding detection to multi-task learning for chest CT and points to practical benefits and remaining data-driven challenges for robust lesion detection.
Abstract
Lung cancer and covid-19 have one of the highest morbidity and mortality rates in the world. For physicians, the identification of lesions is difficult in the early stages of the disease and time-consuming. Therefore, multi-task learning is an approach to extracting important features, such as lesions, from small amounts of medical data because it learns to generalize better. We propose a novel multi-task framework for classification, segmentation, reconstruction, and detection. To the best of our knowledge, we are the first ones who added detection to the multi-task solution. Additionally, we checked the possibility of using two different backbones and different loss functions in the segmentation task.
