AEC-Net: Attention and Edge Constraint Network for Medical Image Segmentation.

Semantic segmentation is a fundamental and challenging problem in medical image analysis. At present, deep convolutional neural network plays a dominant role in medical image segmentation. The existing problems of this field are making less use of image information and learning few edge features, which may lead to the ambiguous boundary and inhomogeneous intensity distribution of the result. Since the characteristics of different stages are highly inconsistent, these two cannot be directly combined. In this paper, we proposed the Attention and Edge Constraint Network (AEC-Net) to optimize features by introducing attention mechanisms in the lower-level features, so that it can be better combined with higher-level features. Meanwhile, an edge branch is added to the network which can learn edge and texture features simultaneously. We evaluated this model on three datasets, including skin cancer segmentation, vessel segmentation, and lung segmentation. Results demonstrate that the proposed model has achieved state-of-the-art performance on all datasets.

An objective comparison of detection and segmentation algorithms for artefacts in clinical endoscopy.

We present a comprehensive analysis of the submissions to the first edition of the Endoscopy Artefact Detection challenge (EAD). Using crowd-sourcing, this initiative is a step towards understanding the limitations of existing state-of-the-art computer vision methods applied to endoscopy and promoting the development of new approaches suitable for clinical translation. Endoscopy is a routine imaging technique for the detection, diagnosis and treatment of diseases in hollow-organs; the esophagus, stomach, colon, uterus and the bladder. However the nature of these organs prevent imaged tissues to be free of imaging artefacts such as bubbles, pixel saturation, organ specularity and debris, all of which pose substantial challenges for any quantitative analysis. Consequently, the potential for improved clinical outcomes through quantitative assessment of abnormal mucosal surface observed in endoscopy videos is presently not realized accurately. The EAD challenge promotes awareness of and addresses this key bottleneck problem by investigating methods that can accurately classify, localize and segment artefacts in endoscopy frames as critical prerequisite tasks. Using a diverse curated multi-institutional, multi-modality, multi-organ dataset of video frames, the accuracy and performance of 23 algorithms were objectively ranked for artefact detection and segmentation. The ability of methods to generalize to unseen datasets was also evaluated. The best performing methods (top 15%) propose deep learning strategies to reconcile variabilities in artefact appearance with respect to size, modality, occurrence and organ type. However, no single method outperformed across all tasks. Detailed analyses reveal the shortcomings of current training strategies and highlight the need for developing new optimal metrics to accurately quantify the clinical applicability of methods.