MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria.
Neuroimage. 2011 Sep 15;58(2):588-94. doi: 10.1016/j.neuroimage.2011.06.078. Epub 2011 Jul 2.
Exact timing is essential for functional MRI data analysis. Datasets are commonly measured using repeated 2D imaging methods, resulting in a temporal offset between slices. To compensate for this timing difference, slice-timing correction (i.e. temporal data interpolation) has been used as an fMRI pre-processing step for more than fifteen years. However, there has been an ongoing debate about the effectiveness and applicability of this method. This paper presents the first elaborated analysis of the impact of the slice-timing effect on simulated data for different fMRI paradigms and measurement parameters, taking into account data noise and smoothing effects. Here we show, depending on repetition time and paradigm design, slice-timing effects can significantly impair fMRI results and slice-timing correction methods can successfully compensate for these effects and therefore increase the robustness of the data analysis. In addition, our results from simulated data were supported by empirical in vivo datasets. Our findings suggest that slice-timing correction should be included in the fMRI pre-processing pipeline.
精确的时间安排对于功能磁共振成像数据分析至关重要。数据集通常使用重复的 2D 成像方法进行测量，这会导致切片之间存在时间偏移。为了弥补这种时间差异，已经将切片时间校正（即时间数据插值）作为 fMRI 预处理步骤使用了超过十五年。然而，关于该方法的有效性和适用性一直存在争议。本文首次对不同 fMRI 范式和测量参数下模拟数据中切片时间效应的影响进行了详细分析，同时考虑了数据噪声和平滑效应。研究结果表明，取决于重复时间和范式设计，切片时间效应会显著影响 fMRI 结果，而切片时间校正方法可以成功地补偿这些效应，从而提高数据分析的稳健性。此外，模拟数据的结果得到了体内经验数据集的支持。这些发现表明，应该在 fMRI 预处理管道中包含切片时间校正。
