Implanted medical devices or other strong sources of interference are not barriers to magnetoencephalographic recordings in epilepsy patients.
Implanted medical devices or other strong sources of interference are not barriers to magnetoencephalographic recordings in epilepsy patients.
复制标题
植入的医疗设备或其他强干扰源不会妨碍癫痫患者的脑磁图记录。
DOI：
10.1016/j.clinph.2013.04.004
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Burgess,RichardC
中科院分区：
文献类型：
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作者：
Jin,Kazutaka;Alexopoulos,AndreasV;Mosher,JohnC;Burgess,RichardC
目的脑电图（MEG）记录的定位精度高度依赖于信噪比，而信噪比难以控制。我们对数据进行了后处理，以便用等效电流偶极子方法将噪声降低到允许足够的源定位的水平。采用204个平面梯度仪和102个磁力计组成的全头脑磁图系统记录30例连续癫痫患者的脑电。回顾数据以确定间隔尖峰。采用时空信号空间分离（tSSS）方法进行初步分析。在不使用tSSS的情况下，对15例患者的18个偶极子簇进行重新分析，比较处理前后可接受偶极子的数量、拟合优度和位置。结果在18个聚类中，有8个聚类在处理前捕获了可接受的偶极子聚类，但tSSS对所有参数均有明显改善。另外5组均来自使用迷走神经刺激器的患者，在处理前很少或没有可接受的偶极子，但tSSS获得了足够的偶极子簇。结论与志愿者研究对象相比，不能期望临床患者完全配合，其MEG数据可能包含更多干扰。本研究表明，用一种消除脑外伪影的方法处理脑磁图数据可以显著提高数据质量。在某些情况下，这种改进可能意味着满意的偶极子拟合与不可能定位之间的差异。
OBJECTIVELocalization accuracy in magnetoencephalography (MEG) recordings is highly dependent on signal to noise ratio, which is difficult to control.METHODSWe have post-processed our data in order to reduce noise to a level permitting adequate source localization with equivalent current dipole methods. In 30 consecutive epilepsy patients, MEG was recorded using a whole-head MEG system consisting of 204 planar gradiometer and 102 magnetometers, with simultaneous EEG. Data were reviewed to identify interictal spikes. The initial analysis was done after employing a spatiotemporal signal space separation (tSSS) method. A total of 18 dipole clusters in 15 patients were reanalyzed without tSSS, to compare the number, goodness of fit, and locations of acceptable dipoles before and after processing.RESULTSIn 8 of 18 clusters, although acceptable dipole clusters were captured before processing, there was a clear improvement of all parameters with tSSS. In another 5 clusters, all from patients with vagus nerve stimulators, there were few or no acceptable dipoles before processing, but sufficient dipole clusters were obtained with tSSS.CONCLUSIONIn contrast to volunteer research subjects, clinical patients cannot be expected to cooperate as fully, and their MEG data are likely to include more interference. This study demonstrates that processing the MEG data with a method to eliminate artifact arising from outside the brain significantly improves the data.SIGNIFICANCEIn some cases, this improvement can mean the difference between satisfactory dipole fits vs no possible localization.