A Bidirectional Context Propagation Network for Urine Sediment Particle Detection in Microscopic Images

The microscopic urine sediment examination is a crucial part in the evaluation of renal and urinary tract diseases. Recently, there are emerging CNNs-based detectors to detect the urine sediment particles in an end-to-end manner. However, it is not very compatible to transfer CNNs-based detector directly from natural images application to microscopic images, especially in which small objects are in majority. This paper proposes a bidirectional context propagation network called BCPNet for urine sediment particle detection. In BCPNet, spatial details encoded by shallow convolutional layers are propagated upward to improve the localisation ability of deep features. On the contrary, high semantic information encoded by deep convolutional layers is propagated downward to enhance the distinctiveness of shallow features. With the refinement by convolutional block attention modules, the enriched features are more powerful to both localisation and classification. Experimental results on urine sediment particle dataset USE demonstrate effectiveness of the proposed BCPNet.