Influences of skull segmentation inaccuracies on EEG source analysis
Influences of skull segmentation inaccuracies on EEG source analysis
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DOI：
10.1016/j.neuroimage.2012.05.006
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发表时间：
2012-08-01
期刊：
影响因子：
5.7
通讯作者：
Wolters, C. H.
中科院分区：
文献类型：
--
作者：
Lanfer, B.;Scherg, M.;Wolters, C. H.
众所周知，低导电性的人类头骨对脑电图（EEG）源分析有特别大的影响。由于难以从磁共振图像中分割出复杂的颅骨几何形状，用于脑电图源分析的体积导体模型可能包含关于颅骨几何形状的不准确和简化。本文的计算机仿真研究探讨了各种颅骨几何缺陷对脑电正演模拟和脑电数据源重构的影响。参考脑电图数据在一个详细的、解剖学上合理的参考模型中进行模拟。测试模型是在参考模型的基础上推导出来的，代表了颅骨几何形状的各种不精确和简化。这些错误包括错误的颅骨孔，颅骨厚度的局部错误，将空腔建模为骨骼，将模型向下延伸，将下颅骨或下颅骨和头皮简化为恒定厚度的层。将参考EEG数据与测试模型中的正演模拟进行对比，并对模拟参考数据进行测试模型中的源重构。所有正演模拟均采用高分辨率网格有限元法。研究发现，靠近源空间的颅骨几何精度较大，例如，在颅骨正下方切割模型时，会导致扩展源空间区域的误差达到20 mm以上。局部缺陷，例如，错误的颅骨孔，仅在缺陷附近引起不可忽略的误差。研究设计允许对影响大小进行比较，并得出颅骨几何形状建模的指导方针。(C) 2012爱思唯尔公司版权所有。
The low-conducting human skull is known to have an especially large influence on electroencephalography (EEG) source analysis. Because of difficulties segmenting the complex skull geometry out of magnetic resonance images, volume conductor models for EEG source analysis might contain inaccuracies and simplifications regarding the geometry of the skull. The computer simulation study presented here investigated the influences of a variety of skull geometry deficiencies on EEG forward simulations and source reconstruction from EEG data.Reference EEG data was simulated in a detailed and anatomically plausible reference model. Test models were derived from the reference model representing a variety of skull geometry inaccuracies and simplifications. These included erroneous skull holes, local errors in skull thickness, modeling cavities as bone, downward extension of the model and simplifying the inferior skull or the inferior skull and scalp as layers of constant thickness.The reference EEG data was compared to forward simulations in the test models, and source reconstruction in the test models was performed on the simulated reference data. The finite element method with high-resolution meshes was employed for all forward simulations.It was found that large skull geometry inaccuracies close to the source space, for example, when cutting the model directly below the skull, led to errors of 20 mm and more for extended source space regions. Local defects, for example, erroneous skull holes, caused non-negligible errors only in the vicinity of the defect. The study design allowed a comparison of influence size, and guidelines for modeling the skull geometry were concluded. (C) 2012 Elsevier Inc. All rights reserved.