Movement-related effects in fMRI time-series
Movement-related effects in fMRI time-series
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DOI：
10.1002/mrm.1910350312
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发表时间：
1996-03-01
影响因子：
3.3
通讯作者：
Turner, R
中科院分区：
文献类型：
--
作者：
Friston, KJ;Williams, S;Turner, R
本文涉及的空间和强度的转换，需要调整受试者的运动在功能磁共振成像（fMRI）激活研究的混杂效应，提出了一种方法，模型，并删除，运动相关的伪影从fMRI时间序列。该方法基于这样的观察，即即使在完美的重新对准之后，运动相关效应也是存在的。运动相关效应可以被分为作为扫描仪的参考系中的对象的位置的函数的那些效应和由于先前扫描中的运动而引起的那些效应，该第二分量取决于小体积中的自旋所经历的激发的历史以及随之而来的局部饱和度的差异，因此，自旋激发历史本身将是先前位置的函数，这表明先前位移对当前信号的影响的自回归移动平均模型。描述了模型以及随后的运动相关分量的调整，实证分析表明，（在极端情况下）超过90%的fMRI信号可以归因于运动，并且可以成功地去除这种人为成分。
This paper concerns the spatial and intensity transformations that are required to adjust for the confounding effects of subject movement during functional MRI (fMRI) activation studies, An approach is presented that models, and removes, movement-related artifacts from fMRI time-series. This approach is predicated on the observation that movement-related effects are extant even after perfect realignment, Movement-related effects can be divided into those that are a function of position of the object in the frame of reference of the scanner and those that are due to movement in previous scans, This second component depends on the history of excitation experienced by spins in a small volume and consequent differences in local saturation, The spin excitation history thus will itself be a function of previous positions, suggesting an autoregression-moving average model for the effects of previous displacements on the current signal, A model is described as well as the adjustments for movement-related components that ensue, The empirical analyses suggest that (in extreme situations) over 90% of fMRI signal can be attributed to movement, and that this artifactual component can be successfully removed.