Aurich Nathassia K, Alves Filho José O, Marques da Silva Ana M, Franco Alexandre R
Faculdade de Engenharia, PUCRS Porto Alegre, Brazil.
Faculdade de Engenharia, PUCRS Porto Alegre, Brazil ; Instituto do Cérebro do Rio Grande do Sul (InsCer-RS), PUCRS Porto Alegre, Brazil ; Faculdade de Física, PUCRS Porto Alegre, Brazil.
Front Neurosci. 2015 Feb 19;9:48. doi: 10.3389/fnins.2015.00048. eCollection 2015.
With resting-state functional MRI (rs-fMRI) there are a variety of post-processing methods that can be used to quantify the human brain connectome. However, there is also a choice of which preprocessing steps will be used prior to calculating the functional connectivity of the brain. In this manuscript, we have tested seven different preprocessing schemes and assessed the reliability between and reproducibility within the various strategies by means of graph theoretical measures. Different preprocessing schemes were tested on a publicly available dataset, which includes rs-fMRI data of healthy controls. The brain was parcellated into 190 nodes and four graph theoretical (GT) measures were calculated; global efficiency (GEFF), characteristic path length (CPL), average clustering coefficient (ACC), and average local efficiency (ALE). Our findings indicate that results can significantly differ based on which preprocessing steps are selected. We also found dependence between motion and GT measurements in most preprocessing strategies. We conclude that by using censoring based on outliers within the functional time-series as a processing, results indicate an increase in reliability of GT measurements with a reduction of the dependency of head motion.
使用静息态功能磁共振成像(rs-fMRI)时,有多种后处理方法可用于量化人类大脑连接组。然而,在计算大脑功能连接之前,对于使用哪些预处理步骤也存在选择。在本手稿中,我们测试了七种不同的预处理方案,并通过图论测量评估了各种策略之间的可靠性和策略内部的可重复性。在一个公开可用的数据集上测试了不同的预处理方案,该数据集包括健康对照的rs-fMRI数据。将大脑划分为190个节点,并计算了四种图论(GT)测量指标;全局效率(GEFF)、特征路径长度(CPL)、平均聚类系数(ACC)和平均局部效率(ALE)。我们的研究结果表明,根据选择的预处理步骤,结果可能会有显著差异。我们还发现在大多数预处理策略中,运动与GT测量之间存在相关性。我们得出结论,通过将基于功能时间序列中的异常值进行的审查作为一种处理方式,结果表明GT测量的可靠性有所提高,同时头部运动的相关性降低。