Properties of the ballistocardiogram artefact as revealed by EEG recordings at 1.5, 3 and 7 T static magnetic field strength
Properties of the ballistocardiogram artefact as revealed by EEG recordings at 1.5, 3 and 7 T static magnetic field strength
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DOI：
10.1016/j.ijpsycho.2007.05.015
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发表时间：
2008-03-01
影响因子：
3
通讯作者：
Bowtell, Richard W.
中科院分区：
文献类型：
--
作者：
Debener, Stefan;Mullinger, Karen J.;Bowtell, Richard W.
与功能磁共振成像 (fMRI) 同时记录的脑电图 (EEG) 数据存在严重的伪影。尤其是心冲击描记图 (BCG) 伪影目前还知之甚少，并且已经提出了不同的 BCG 去除策略。在本研究中，四名参与者在场强分别为 1.5、3 和 7 T 的 3 台不同 MRI 扫描仪中记录了 EEG 数据，目的是研究静磁场强度对 BCG 伪影和独立成分分析 (ICA) 的影响。结果证实 BCG 伪影的幅度是静磁场强度的函数。此外，BCG 伪影的空间变异性在较高磁场强度下显着增加。逐通道 BCG 校正前后 ICA 的比较表明，在逐通道 BCG 校正后应用 ICA 时，可以更容易地识别典型的独立分量。对脑电图辅助心电图记录的进一步分析表明，至少有两个不同的过程对 BCG 的起源有贡献，一方面是血液运动或头部轴向旋转油，另一方面是头部横向部位的电极运动。这在初步的 BCG 模型中进行了总结，该模型可能有助于解释最近关于 ICA 对于 BCG 去除的有用性的不一致。它还可以指导未来开发更先进的卡介苗去除程序。 (C) 2007 Elsevier B.V. 保留所有权利。
Electroencephalogram (EEG) data recorded simultaneously with functional magnetic resonance imaging (fMRI) suffer from severe artefacts. The ballistocardiogram (BCG) artefact in particular is as yet poorly understood and different BCG removal strategies have been proposed. In the present study, EEG data were recorded from four participants in three different MRI scanners with field strengths of 1.5, 3 and 7 T, with the aim of investigating the impact of the static magnetic field strength on the BCG artefact and independent component analysis (ICA). The results confirm that the amplitude of the BCG artefact is a function of the static magnetic field strength. Moreover, the spatial variability of the BCG artefact substantially increased at higher magnetic field strengths. A comparison of ICA before and after channel-wise BCG correction revealed that typical independent components could be more easily identified when ICA was applied after channel-wise BCG correction. Further analysis of EEG aid electrocardiogram recordings points towards the contribution of at least two different processes to the origin of the BCG, which are blood movement or axial head rotation oil the one hand and electrode movement at lateral sites of the head on the other. This is summarized in a preliminary BCG model that may help to explain recent inconsistencies regarding the usefulness of ICA for BCG removal. It may also guide the future development of more advanced BCG removal procedures. (C) 2007 Elsevier B.V. All rights reserved.