title: Slice-timing effects and their correction in functional MRI.
abstract: 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.
authors.affiliation: MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria. ronald.sladky@meduniwien.ac.at
authors.forename: Ronald
authors.initials: R
authors.lastname: Sladky
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Friston
authors.forename: Jasmin
authors.initials: J
authors.lastname: Tröstl
authors.forename: Ross
authors.initials: R
authors.lastname: Cunnington
authors.forename: Ewald
authors.initials: E
authors.lastname: Moser
authors.forename: Christian
authors.initials: C
authors.lastname: Windischberger
mesh_terms: D000328:Adult; D000465:Algorithms; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016011:Normal Distribution; D055815:Young Adult