arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2602.00348cs.CV
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MASC: 通过强化学习进行金属感知采样与校正以加速MRI

MASC: Metal-Aware Sampling and Correction via Reinforcement Learning for Accelerated MRI

Vanderbilt University(范德比尔特大学);Vanderbilt University Medical Center(范德比尔特大学医学中心);Oak Ridge National Laboratory(橡树岭国家实验室)
Zhengyi Lu, Ming Lu, Chongyu Qu, Junchao Zhu, Junlin Guo, Marilyn Lionts, Yanfan Zhu, Yuechen Yang, Tianyuan Yao, Jayasai Rajagopal, Bennett Allan Landman, Xiao… 展开作者

Zhengyi Lu, Ming Lu, Chongyu Qu, Junchao Zhu, Junlin Guo, Marilyn Lionts, Yanfan Zhu, Yuechen Yang, Tianyuan Yao, Jayasai Rajagopal, Bennett Allan Landman, Xiao Wang, Xinqiang Yan, Yuankai Huo

AI总结:

MASC通过强化学习联合优化金属感知的k空间采样和伪影校正,提升加速MRI的图像质量与诊断效果。

摘要:

MRI中的金属植入物会引起严重的伪影,从而降低图像质量并阻碍临床诊断。传统方法将金属伪影减少(MAR)和加速MRI采集视为两个独立的问题。我们提出MASC,一种统一的强化学习框架,旨在联合优化金属感知的k空间采样和伪影校正以实现加速MRI。为了实现监督训练,我们构建了一个配对的MRI数据集,利用物理基础的模拟生成具有和不具有金属植入物的仿真的k空间数据和重建图像。这个配对数据集提供了具有和不具有金属植入物的模拟3DMRI扫描,其中每个金属污染的样本都有一个精确匹配的干净参考,使直接监督用于伪影减少和采集策略学习成为可能。我们将主动MRI采集视为一个顺序决策问题,其中一个伪影感知的近端策略优化(PPO)智能体在有限的采集预算下学习选择k空间相位编码线。该智能体在经过U-Net基于的MAR网络处理的欠采样重建图像上运行,学习提高重建质量的模式。我们进一步提出了一种端到端的训练方案,其中采集策略学习选择支持伪影去除的最佳k空间线,同时MAR网络同时适应由此产生的欠采样模式。实验表明,MASC学习的策略优于传统采样策略,端到端训练相比使用冻结的预训练MAR网络提高了性能,验证了联合优化的优势。在FastMRI上的跨数据集实验进一步确认了对现实临床MRI数据的泛化能力。MASC的代码和模型已公开发布:https://github.com/hrlblab/masc

英文摘要:

Metal implants in MRI cause severe artifacts that degrade image quality and hinder clinical diagnosis. Traditional approaches address metal artifact reduction (MAR) and accelerated MRI acquisition as separate problems. We propose MASC, a unified reinforcement learning framework that jointly optimizes metal-aware k-space sampling and artifact correction for accelerated MRI. To enable supervised training, we construct a paired MRI dataset using physics-based simulation, generating k-space data and reconstructions for phantoms with and without metal implants. This paired dataset provides simulated 3D MRI scans with and without metal implants, where each metal-corrupted sample has an exactly matched clean reference, enabling direct supervision for both artifact reduction and acquisition policy learning. We formulate active MRI acquisition as a sequential decision-making problem, where an artifact-aware Proximal Policy Optimization (PPO) agent learns to select k-space phase-encoding lines under a limited acquisition budget. The agent operates on undersampled reconstructions processed through a U-Net-based MAR network, learning patterns that maximize reconstruction quality. We further propose an end-to-end training scheme where the acquisition policy learns to select k-space lines that best support artifact removal while the MAR network simultaneously adapts to the resulting undersampling patterns. Experiments demonstrate that MASC's learned policies outperform conventional sampling strategies, and end-to-end training improves performance compared to using a frozen pre-trained MAR network, validating the benefit of joint optimization. Cross-dataset experiments on FastMRI with physics-based artifact simulation further confirm generalization to realistic clinical MRI data. The code and models of MASC have been made publicly available: https://github.com/hrlblab/masc

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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