Gülle Merve, Akçakaya Mehmet
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA.
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
Proc IEEE Int Symp Biomed Imaging. 2024 May;2024. doi: 10.1109/isbi56570.2024.10635530. Epub 2024 Aug 22.
Real-time dynamic MRI is important for visualizing time-varying processes in several applications, including cardiac imaging, where it enables free-breathing images of the beating heart without ECG gating. However, current real-time MRI techniques commonly face challenges in achieving the required spatio-temporal resolutions due to limited acceleration rates. In this study, we propose a deep learning (DL) technique for improving the estimation of stationary outer-volume signal from shifted time-interleaved undersampling patterns. Our approach utilizes the pseudo-periodic nature of the ghosting artifacts arising from the moving organs. Subsequently, this estimated outer-volume signal is subtracted from individual timeframes of the real-time MR time series, and each timeframe is reconstructed individually using physics-driven DL methods. Results show improved image quality at high acceleration rates, where conventional methods fail.
实时动态磁共振成像(MRI)在多种应用中对于可视化随时间变化的过程非常重要,包括心脏成像,在心脏成像中它能够在无需心电图门控的情况下获取跳动心脏的自由呼吸图像。然而,由于加速率有限,当前的实时MRI技术在实现所需的时空分辨率方面通常面临挑战。在本研究中,我们提出了一种深度学习(DL)技术,用于改进从移位时间交织欠采样模式估计静止外容积信号。我们的方法利用了由移动器官产生的重影伪影的伪周期性。随后,从实时MR时间序列的各个时间帧中减去这个估计的外容积信号,并使用物理驱动的DL方法分别重建每个时间帧。结果表明,在传统方法失效的高加速率下,图像质量得到了改善。