Multibranch Learning for Angiodysplasia Segmentation with Attention-Guided Networks and Domain Adaptation

As a common cause of anemia and gastrointestinal bleeding, angiodysplasia (AD) diagnosis in wireless capsule endoscopy (WCE) images is important in clinical. Current manual review requires undivided concentration of the gastroenterologists, which is laborious and time-consuming. The development of computational methods that can assist automated diagnosis of angiodysplasia is highly desirable. In this paper, we present a new approach, ADNet, for angiodysplasia segmentation using convolutional neural networks (CNNs). Compared with previous learning strategies, ADNet gains accuracy from attentionguided and domain-adversarial training via a multibranch CNN architecture. Specifically, the core branch is constructed for AD segmentation in a fully convolutional manner. Then we propose an attention module embedded in the attention branch to enhance network feature learning, which allows ADNet to focus on the most informative and AD relevant regions while processing. Furthermore, an adaptation branch is built to learn domain-invariant features by adversarial training, aiming to improve the performance when datasets are expanded while preventing the degradation induced by the variations in WCE image acquisition. ADNet is evaluated using two WCE datasets with angiodysplasia and the results show the accuracy gains we obtain, where the state-of-the-art segmentation performance on the public dataset of GIANA’17 is achieved.