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Low-Dose CT Imaging Using a Regularization-Enhanced Efficient Diffusion Probabilistic Model

Medical Physics 2025-10-29 v1

Abstract

Low-dose computed tomography (LDCT) reduces patient radiation exposure but introduces substantial noise that degrades image quality and hinders diagnostic accuracy. Existing denoising approaches often require many diffusion steps, limiting real-time applicability. We propose a Regularization-Enhanced Efficient Diffusion Probabilistic Model (RE-EDPM), a rapid and high-fidelity LDCT denoising framework that integrates a residual shifting mechanism to align low-dose and full-dose distributions and performs only four reverse diffusion steps using a Swin-based U-Net backbone. A composite loss combining pixel reconstruction, perceptual similarity (LPIPS), and total variation (TV) regularization effectively suppresses spatially varying noise while preserving anatomical structures. RE-EDPM was evaluated on a public LDCT benchmark across dose levels and anatomical sites. On 10 percent dose chest and 25 percent dose abdominal scans, it achieved SSIM = 0.879 (0.068), PSNR = 31.60 (2.52) dB, VIFp = 0.366 (0.121) for chest, and SSIM = 0.971 (0.000), PSNR = 36.69 (2.54) dB, VIFp = 0.510 (0.007) for abdomen. Visual and statistical analyses, including ablation and Wilcoxon signed-rank tests (p < 0.05), confirm significant contributions from residual shifting and regularization terms. RE-EDPM processes two 512x512 slices in about 0.25 s on modern GPUs, supporting near real-time clinical use. The proposed framework achieves an optimal balance between noise suppression and anatomical fidelity, offering an efficient solution for LDCT restoration and broader medical image enhancement tasks.

Keywords

Cite

@article{arxiv.2510.23859,
  title  = {Low-Dose CT Imaging Using a Regularization-Enhanced Efficient Diffusion Probabilistic Model},
  author = {Qiang Li and Mojtaba Safari and Shansong Wang and Huiqiao Xie and Jie Ding and Tonghe Wang and Xiaofeng Yang},
  journal= {arXiv preprint arXiv:2510.23859},
  year   = {2025}
}
R2 v1 2026-07-01T07:08:37.712Z