Parker David B, Razlighi Qolamreza R
Department of Biomedical Engineering, Columbia University, New York, NY, United States.
Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, United States.
Front Neurosci. 2019 Aug 20;13:821. doi: 10.3389/fnins.2019.00821. eCollection 2019.
Due to the nature of fMRI acquisition protocols, slices cannot be acquired simultaneously, and as a result, are temporally misaligned from each other. To correct from this misalignment, preprocessing pipelines often incorporate slice timing correction (STC). However, evaluating the benefits of STC is challenging because it (1) is dependent on slice acquisition parameters, (2) interacts with head movement in a non-linear fashion, and (3) significantly changes with other preprocessing steps, fMRI experimental design, and fMRI acquisition parameters. Presently, the interaction of STC with various scan conditions has not been extensively examined. Here, we examine the effect of STC when it is applied with various other preprocessing steps such as motion correction (MC), motion parameter residualization (MPR), and spatial smoothing. Using 180 simulated and 30 real fMRI data, we quantitatively demonstrate that the optimal order in which STC should be applied depends on interleave parameters and motion level. We also demonstrate the benefit STC on sub-second-TR scans and for functional connectivity analysis. We conclude that STC is a critical part of the preprocessing pipeline that can be extremely beneficial for fMRI processing. However, its effectiveness interacts with other preprocessing steps and with other scan parameters and conditions which may obscure its significant importance in the fMRI processing pipeline.
由于功能磁共振成像(fMRI)采集协议的特性,切片不能同时采集,因此,各切片在时间上相互错位。为了校正这种错位,预处理流程通常会纳入切片时间校正(STC)。然而,评估STC的益处具有挑战性,因为它(1)取决于切片采集参数,(2)以非线性方式与头部运动相互作用,并且(3)会随着其他预处理步骤、fMRI实验设计和fMRI采集参数而发生显著变化。目前,尚未对STC与各种扫描条件的相互作用进行广泛研究。在此,我们研究了STC与各种其他预处理步骤(如运动校正(MC)、运动参数残差化(MPR)和空间平滑)一起应用时的效果。使用180个模拟fMRI数据和30个真实fMRI数据,我们定量证明了应用STC的最佳顺序取决于交错参数和运动水平。我们还展示了STC在亚秒级重复时间(TR)扫描和功能连接分析方面的益处。我们得出结论,STC是预处理流程的关键部分,对fMRI处理可能极其有益。然而,其有效性与其他预处理步骤以及其他扫描参数和条件相互作用,这可能会掩盖其在fMRI处理流程中的重要意义。