Accurate Segmentation of Synaptic Cleft with Contour Growing Concatenated with a Convnet

Synaptic cleft is an important area for neuroscientists to analyze the macromolecular complexes related to neurotransmitter transmission. However, the large amount of noise and low signal-to-noise ratio in raw electron micrographs make it challenging to extract this region automatically. In this paper, we propose a simple but effective framework to automatically extract accurate boundaries of synaptic cleft regions. Our approach concatenates a novel contour growing algorithm to a fully convolutional network (FCN), so that it takes both advantages of large receptive field of FCNs and fine-level localization of contour evolution. The contour growing algorithm is based on the flexible evolving tension and synchronous growing controlling to localize the opening contour of clef region. With consideration of both global localization and local segmentation, our approach is more robust to noisy electron micrographs and outperforms all existing single-model FCNs on accurate segmentation of synaptic clefts.