Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
Magn Reson Med. 2018 Jan;79(1):62-70. doi: 10.1002/mrm.26986. Epub 2017 Oct 27.
To develop a novel acquisition and reconstruction method for magnetization-prepared 3-dimensional multicontrast rapid gradient-echo imaging, using Hankel matrix completion in combination with compressed sensing and parallel imaging.
A random k-space shuffling strategy was implemented in simulation and in vivo human experiments at 7 T for 3-dimensional inversion recovery, T /diffusion preparation, and magnetization transfer imaging. We combined compressed sensing, based on total variation and spatial-temporal low-rank regularizations, and parallel imaging with pixel-wise Hankel matrix completion, allowing the reconstruction of tens of multicontrast 3-dimensional images from 3- or 6-min scans.
The simulation result showed that the proposed method can reconstruct signal-recovery curves in each voxel and was robust for typical in vivo signal-to-noise ratio with 16-times acceleration. In vivo studies achieved 4 to 24 times accelerations for inversion recovery, T /diffusion preparation, and magnetization transfer imaging. Furthermore, the contrast was improved by resolving pixel-wise signal-recovery curves after magnetization preparation.
The proposed method can improve acquisition efficiencies for magnetization-prepared MRI and tens of multicontrast 3-dimensional images could be recovered from a single scan. Furthermore, it was robust against noise, applicable for recovering multi-exponential signals, and did not require any previous knowledge of model parameters. Magn Reson Med 79:62-70, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
开发一种新的采集和重建方法，用于磁化准备的 3 维多对比度快速梯度回波成像，结合汉克尔矩阵完成、压缩感知和并行成像。
在 7T 进行了模拟和人体实验，采用随机 k 空间置换策略进行 3 维反转恢复、T /扩散准备和磁化传递成像。我们结合了基于全变差和时空低秩正则化的压缩感知，以及逐像素汉克尔矩阵完成，允许从 3 分钟或 6 分钟的扫描中重建数十个多对比度 3 维图像。
模拟结果表明，该方法可以重建每个体素的信号恢复曲线，并且对于典型的体内信噪比具有 16 倍的加速能力具有鲁棒性。在体内研究中，反转恢复、T /扩散准备和磁化传递成像的加速比达到 4 到 24 倍。此外，通过在磁化准备后解析逐像素的信号恢复曲线，可以提高对比度。
该方法可以提高磁化准备 MRI 的采集效率，从单次扫描中可以恢复数十个多对比度 3 维图像。此外，它对噪声具有鲁棒性，适用于恢复多指数信号，并且不需要任何模型参数的先验知识。磁共振医学 79：62-70，2018。© 2017 国际磁共振学会。
