Revisiting model scaling with a U-net benchmark for 3D medical image segmentation
Are larger models always better for 3D medical image segmentation? Despite the widespread adoption of 3D U-Net in various medical imaging tasks, this critical question remains underexplored. To challenge the common assumption, we systematically benchmark 18 U-Net variants-adjusting resolution stages, depth, and width-across 42 diverse public datasets. Our findings reveal that the answer is no: optimal architectures are highly task-specific, with smaller models often performing competitively. Specifically, we identify three key insights: (1) increasing resolution stages provides limited benefits for datasets with larger voxel spacing; (2) deeper networks offer limited advantages for anatomically complex shapes; and (3) wider networks provide minimal advantages for tasks with limited segmentation classes. Based on these insights, we provide practical guidelines for optimizing U-Net architectures according to dataset characteristics. Our findings highlight the limitations of the"bigger is better"paradigm while establishing a framework for balancing performance and computational efficiency in 3D medical image segmentation tasks.
Authors
- Lixu Gu
- Zhongying Deng (ORCID: https://orcid.org/0000-0003-0887-7408)
- Yanzhou Su (ORCID: https://orcid.org/0000-0002-3377-469X)
- Junjun He (ORCID: https://orcid.org/0000-0002-1813-1784)
- Yun Gu (ORCID: https://orcid.org/0000-0002-4199-0675)
- Haoyu Wang (ORCID: https://orcid.org/0000-0002-1753-7336)
- Tianbin Li (ORCID: https://orcid.org/0000-0003-2167-586X)
- Jie Liu (ORCID: https://orcid.org/0000-0002-1400-1691)
- Yu Qiao (ORCID: https://orcid.org/0000-0002-2191-3875)
- Ziyan Huang (ORCID: https://orcid.org/0000-0003-3872-6993)
- Shaoting Zhang
- Zhikai Yang (ORCID: https://orcid.org/0000-0001-6104-5083)
Institutions
- Shanghai Jiao Tong University (CN)
- University of Cambridge (GB)
- Sichuan University (CN)
- Beijing Academy of Artificial Intelligence (CN)
- Artificial Intelligence in Medicine (Canada) (CA)
- Shanghai Artificial Intelligence Laboratory (CN)
- Monash University (AU)
- Shanghai Institute of Technology (CN)
- KTH Royal Institute of Technology (SE)
Publication Details
- Journal
- Scientific Reports
- Published
- 2025-08-14
- DOI
- https://doi.org/10.1038/s41598-025-15617-1
- Citations
- 5
- Primary Topic
- Radiomics and Machine Learning in Medical Imaging
- Type
- article
- Field-Weighted Citation Impact
- 6.80
Funders
- Shanghai Jiao Tong University
- National Science and Technology Major Project
- National Key Research and Development Program of China