Learning multi-scale synergic discriminative features for prostate image segmentation

Although deep convolutional neural networks (DCNNs) have been proposed for prostate MR image segmentation, the effectiveness of these methods is often limited by inadequate semantic discrimination and spatial context modeling. To address these issues, we propose a Multi-scale Synergic Discriminative Network (MSD-Net), which includes a shared encoder, a segmentation decoder, and a boundary detection decoder. We further design the cascaded pyramid convolutional block and residual refinement block, and incorporate them and the channel attention block into MSD-Net to exploit the multi-scale spatial contextual information and semantically consistent features of the gland. We also fuse the features from two decoders to boost the segmentation performance, and introduce the synergic multi-task loss to impose the consistence constraint on the joint segmentation and boundary detection. We evaluated MSD-Net against several prostate segmentation methods on three public datasets and achieved an improved accuracy. Our results indicate that the proposed MSD-Net outperforms existing methods with setting the new state-of-the-art for prostate segmentation in magnetic resonance images.