A study of dipole localization accuracy for MEG and EEC using a human skull phantom
A study of dipole localization accuracy for MEG and EEC using a human skull phantom
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DOI：
10.1016/s0013-4694(98)00057-1
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发表时间：
1998-08-01
期刊：
影响因子：
--
通讯作者：
Lewine, JD
中科院分区：
文献类型：
--
作者：
Leahy, RM;Mosher, JC;Lewine, JD
目的：为了研究EEG和MEG偶极子定位的正向和反向技术的准确性，设计和方法：一个人的颅骨模型构建与大脑，头骨和头皮层和现实的相对电导率。32个独立的电流偶极子分布在“大脑”区域内，并分别收集每个偶极子的EEG和MEG数据。从X射线CT数据中提取真正的偶极子位置和方向以及脑、颅骨和头皮层的形态。每个偶极子的位置估计从EEG和MEG数据使用R-MUSIC逆方法和基于球形和现实的头部几何形状的正向模型。额外的计算机模拟进行调查的因素影响定位精度。结果：使用相对简单的局部拟合球的方法的定位误差仅略大于使用边界元法。32个偶极子的平均定位误差为7-8毫米脑电图和脑磁图3毫米，结论：脑磁图的上级性能优于脑电图似乎是因为后者是更敏感的错误所产生的前向模型简化假设有关的头骨，头皮和大脑的导电性。(C)1998爱思唯尔科学爱尔兰有限公司保留所有权利。
Objective: To investigate the accuracy of forward and inverse techniques for EEG and MEG dipole localization.Design and Methods: A human skull phantom was constructed with brain, skull and scalp layers and realistic relative conductivities. Thirty two independent current dipoles were distributed within the 'brain' region and EEG and MEG data collected separately for each dipole. The true dipole locations and orientations and the morphology of the brain, skull and scalp layers were extracted from X-ray CT data. The location of each dipole was estimated from the EEG and MEG data using the R-MUSIC inverse method and forward models based on spherical and realistic head geometries. Additional computer simulations were performed to investigate the factors affecting localization accuracy.Results: Localization errors using the relatively simpler locally fitted sphere approach are only slightly greater than those using a BEM approach. The average localization error over the 32 dipoles was 7-8 mm for EEG and 3 mm for MEG,Conclusion: The superior performance of MEG over EEG appears to be because the latter is more sensitive to errors in the forward model arising from simplifying assumptions concerning the conductivity of the skull, scalp and brain. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.