๐ค AI Summary
To address insufficient fusion of coarse- and fine-grained semantic information in medical image segmentation, this paper proposes PL-Net, a progressive learning network. Methodologically, PL-Net introduces a novel dual-path progressive learning paradigm: (i) Internal Progressive Learning (IPL), which extracts multi-scale receptive field features stepwise within a single forward pass; and (ii) External Progressive Learning (EPL), which sequentially fuses coarse- and fine-grained semantics across training stagesโwithout introducing any additional learnable parameters. Built upon the U-Net architecture, PL-Net integrates multi-scale feature mixing and parameter-free progressive feature decoupling. Evaluated on five mainstream medical segmentation benchmarks, it achieves state-of-the-art or competitive performance while maintaining identical parameter count to standard U-Net. This demonstrates the efficacy of PL-Netโs efficient, lightweight semantic progressive modeling framework.
๐ Abstract
In recent years, deep convolutional neural network-based segmentation methods have achieved state-of-the-art performance for many medical analysis tasks. However, most of these approaches rely on optimizing the U-Net structure or adding new functional modules, which overlooks the complementation and fusion of coarse-grained and fine-grained semantic information. To address these issues, we propose a 2D medical image segmentation framework called Progressive Learning Network (PL-Net), which comprises Internal Progressive Learning (IPL) and External Progressive Learning (EPL). PL-Net offers the following advantages: 1) IPL divides feature extraction into two steps, allowing for the mixing of different size receptive fields and capturing semantic information from coarse to fine granularity without introducing additional parameters; 2) EPL divides the training process into two stages to optimize parameters and facilitate the fusion of coarse-grained information in the first stage and fine-grained information in the second stage. We conducted comprehensive evaluations of our proposed method on five medical image segmentation datasets, and the experimental results demonstrate that PL-Net achieves competitive segmentation performance. It is worth noting that PL-Net does not introduce any additional learnable parameters compared to other U-Net variants.