RMPPNet: residual multiple pyramid pooling network for subretinal fluid segmentation in SD-OCT images

Abstract

Automatic assessment of neurosensory retinal detachment (NRD) plays an important role in the diagnosis and treatment for central serous chorioretinopathy (CSC). In this paper, we propose a novel residual multiple pyramid pooling network (RMPPNet) to segment NRD in the spectral-domain optical coherence tomography (SD-OCT) images. Based on the encoder-decoder architecture, RMPPNet can better deal with receptive field and multi-scale features. In the encoder stage, based on the residual architectures, six striding convolutions are utilized to replace the conventional pooling layers to obtain wider receptive fields. To further explore the multi-scale features, three pyramid pooling modules (PPM) are supplemented in the encoder stage. In the decoder stage, we use multiple transpose convolutions to recover the resolution of feature maps and concatenate the feature maps from the encoder for each transpose convolution layer. Finally, for better and faster training, we propose a novel loss function to constrain the different sets between the true label and the prediction label. Three different datasets are utilized to evaluate the proposed model. The first dataset contains 35 cubes from 23 patients, and all the cubes are diagnosed as CSC with only NRD lesions. Based on the first dataset, the second dataset supplements ten normal cubes without NRD lesions. The proposed model obtains a mean dice similarity coefficient 92.6 ± 5.6 and 90.2 ± 20.5, respectively. The last dataset includes 23 cubes from 12 eyes of 12 patients with NRD lesions. The average quantitative results, i.e., mean true positive volume fraction, positive predictive value and dice similarity coefficient, obtained by the proposed model are 96%, 96.45% and 96.2%, respectively. The proposed model can provide a wider receptive field and more abundant multi-scale features to overcome the defects involved in NRD segmentations, such as various size, low contrast, and weak boundaries. Comparing with state-of-the-art methods, the proposed RMPPNet can produce more reliable results for NRD segmentation with higher mean values and lower standard deviations of quantitative criterion, which indicates the practical application for the clinical diagnosis of CSC.