Department of Computer Science, University of North Carolina, Chapel Hill, NC 27599, USA.
Department of Radiology, University of North Carolina, Chapel Hill, NC 27599, USA; Biomedical Research Imaging Center (BRIC), University of North Carolina, Chapel Hill, NC 27599, USA.
Med Image Anal. 2022 Oct;81:102548. doi: 10.1016/j.media.2022.102548. Epub 2022 Jul 16.
In this paper, we present a robust reconstruction scheme for diffusion MRI (dMRI) data acquired using slice-interleaved diffusion encoding (SIDE). When combined with SIDE undersampling and simultaneous multi-slice (SMS) imaging, our reconstruction strategy is capable of significantly reducing the amount of data that needs to be acquired, enabling high-speed diffusion imaging for pediatric, elderly, and claustrophobic individuals. In contrast to the conventional approach of acquiring a full diffusion-weighted (DW) volume per diffusion wavevector, SIDE acquires in each repetition time (TR) a volume that consists of interleaved slice groups, each group corresponding to a different diffusion wavevector. This strategy allows SIDE to rapidly acquire data covering a large number of wavevectors within a short period of time. The proposed reconstruction method uses a diffusion spectrum model and multi-dimensional total variation to recover full DW images from DW volumes that are slice-undersampled due to unacquired SIDE volumes. We formulate an inverse problem that can be solved efficiently using the alternating direction method of multipliers (ADMM). Experiment results demonstrate that DW images can be reconstructed with high fidelity even when the acquisition is accelerated by 25 folds.
在本文中，我们提出了一种针对使用切片交错扩散编码（SIDE）采集的扩散磁共振成像（dMRI）数据的鲁棒重建方案。当与 SIDE 欠采样和同时多切片（SMS）成像结合使用时，我们的重建策略能够显著减少需要采集的数据量，从而实现儿科、老年和幽闭恐惧症患者的高速扩散成像。与传统的每扩散波矢量获取完整扩散加权（DW）体积的方法不同，SIDE 在每个重复时间（TR）获取一个由交错的切片组组成的体积，每个组对应于不同的扩散波矢量。这种策略允许 SIDE 在短时间内快速采集覆盖大量波矢量的数据。所提出的重建方法使用扩散谱模型和多维全变分从由于未采集的 SIDE 体积而导致切片欠采样的 DW 体积中恢复全 DW 图像。我们提出了一个可以使用交替方向乘子法（ADMM）有效解决的反问题。实验结果表明，即使采集速度提高 25 倍，也可以高保真地重建 DW 图像。
