arXiv:2502.11259physics.med-phcs.CV2025-02被引 1

用优化稳定性提升深度先验去噪效果,保留细节并确保定量准确。

Exploiting network optimization stability for enhanced PET image denoising using deep image prior

  • 通过分析优化轨迹中的稳定性,生成稳定性图指导去噪
  • 在不同低剂量下噪声抑制更强,峰谷比优于现有方法
  • 适合需要高保真度的PET图像重建,尤其低剂量场景

PET受示踪剂剂量和扫描时间限制,存在统计噪声,影响诊断性能与定量准确性。尽管基于深度学习(DL)的去噪方法可提升图像质量,但可能引入过度平滑,损害定量精度。本文提出一种增强条件深度图像先验(DIP)可靠性的方法,引入优化过程中的稳定性信息,识别网络优化轨迹中不稳定的区域。通过多步中间输出构建稳定性图,将DIP输出与原始重建图像进行加权线性组合,获得最终去噪图像。该方法在脑FDG图像中有效降低噪声,同时保留微小结构细节。实验表明,在多种低剂量条件下,本方法在峰谷比和噪声抑制方面均优于现有方法。感兴趣区分析显示,该方法未引入低估或高估,保持了定量准确性。进一步应用于全剂量PET数据,结果表明该方法显著降低背景噪声,同时维持峰谷比接近未滤波全剂量图像水平。该方法为基于DL的PET去噪提供了稳健方案,提升了可靠性并保障定量精度,具有拓展高灵敏度PET成像能力的潜力。

原文摘要 · Abstract (English)

PET is affected by statistical noise due to constraints on tracer dose and scan duration, impacting both diagnostic performance and quantitative accuracy. While deep learning (DL)-based PET denoising methods have been used to improve image quality, they may introduce over-smoothing, compromising quantitative accuracy. We propose a method for making a DL solution more reliable and apply it to the conditional deep image prior (DIP). We introduce the idea of stability information in the optimization process of conditional DIP, enabling the identification of unstable regions within the network's optimization trajectory. Our method incorporates a stability map, which is derived from multiple intermediate outputs of moderate network at different optimization steps. The final denoised image is then obtained by computing linear combination of the DIP output and the original reconstructed image, weighted by the stability map. Our method effectively reduces noise while preserving small structure details in brain FDG images. Results demonstrated that our approach outperformed existing methods in peak-to-valley ratio and noise suppression across various low-dose levels. Region-of-interest analysis confirmed that the proposed method maintains quantitative accuracy without introducing under- or over-estimation. We applied our method to full-dose PET data to assess its impact on image quality. The results revealed that the proposed method significantly reduced background noise while preserving the peak-to-valley ratio at a level comparable to that of unfiltered full-dose PET images. The proposed method introduces a robust approach to DL-based PET denoising, enhancing its reliability and preserving quantitative accuracy. This strategy has the potential to advance performance in high-sensitivity PET scanners, demonstrating that DL can extend PET imaging capabilities beyond low-dose applications.

PET去噪深度先验稳定性分析图像重建

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