Automatic segmentation model and training
RCU
In this study, 3D Res-UNet, the classical U-net scheme combined with a residual connection unit (RCU), was used for the automatic segmentation task. Five residual units were added to the automatic segmentation model in this study, The model uses a kernel size of (3, 3, 3) and varying number of channels (16, 32, 64, 128, 256) to build the layers of the encoder and decoder. It uses a stride of two to downsample the spatial dimensions of the encoder and residual units with batch normalization to improve the model’s robustness. The architecture of the automatic segmentation model is shown in 