Progressive Stepwise Diffusion Model with Dual Decoders for Semi-Supervised Medical Image Segmentation

Semi-supervised medical image segmentation tasks aim to harness the potential of vast amounts of unlabeled data using a limited amount of annotated data. Denoising Diffusion Probabilistic Models, which have achieved significant success in image generation, are gradually being explored for their potential in semantic image segmentation. However, their application in semi-supervised medical image segmentation is still in its early stages. Initially, due to the high randomness of diffusion models, the pseudo-labels generated during the early training phase may mislead the processing of unlabeled data. Additionally, the use of fixed-time steps for random sampling during training limits the ability of the model to learn effective denoising functions at an early stage. To address these issues, we propose an innovative framework named Progressive Stepwise Diffusion Network with Dual Decoders (PSDD) for semi-supervised medical image segmentation. This framework incorporates an additional normal decoder into the denoising diffusion encoder-decoder structure to provide more accurate labels and employs a Progressive Incremental Step strategy to gradually train the model for longer generation processes. Evaluated on two 2D colon polyp segmentation datasets and a 3D Left Atrium dataset, the experimental results demonstrate significant performance improvements over current advanced methods, thereby validating the effectiveness and potential of this framework in handling complex semi-supervised learning scenarios.