Coarse-to-Fine Stacked Fully Convolutional Nets for lymph node segmentation in ultrasound images

Ultrasound as a well-established imaging modality is widely used in imaging lymph nodes for clinical diagnosis and disease analysis. Quantitative analysis of lymph node features, morphology, and relations can provide valuable information for diagnosis and immune system studies. For such analysis, it is necessary to first accurately segment the lymph node areas in ultrasound images. In this paper, we develop a new deep learning method, called Coarse-to-Fine Stacked Fully Convolutional Nets (CFS-FCN), for automatically segmenting lymph nodes in ultrasound images. Our method consists of multiple stages of FCN modules. We train the CFS-FCN model to learn the segmentation knowledge from a coarse-to-fine, simple-to-complex manner. A data set of 80 ultrasound images containing both normal and diseased lymph nodes is used in our experiments, which show that our method considerably outperforms the state-of-the-art deep learning methods for lymph node segmentation.