Magnetoencephalography for clinical pediatrics: The effect of head positioning on measurement of somatosensory-evoked fields
Magnetoencephalography for clinical pediatrics: The effect of head positioning on measurement of somatosensory-evoked fields
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DOI：
10.1016/j.clinph.2008.04.291
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发表时间：
2008-08-01
影响因子：
4.7
通讯作者：
Pang, E. W.
中科院分区：
文献类型：
--
作者：
Gaetz, W.;Otsubo, H.;Pang, E. W.
目的：目前，全头脑磁图系统的设计，以适应成人头部，从而引入了一个技术问题，独特的儿科脑磁图。已知磁场强度作为1/距离（2）的函数而减小。对于儿科患者，我们质疑重新定位头部以最小化预期源位置与MEG传感器阵列之间的距离是否会显著改善源测量。方法：对17例儿童进行体感诱发电位（SEFs）记录（平均= 4.96岁），头部位于MEG中心，然后横向重新定位以减小皮层源和传感器之间的距离。对等效电流偶极源（ECD）模型进行了残差方差（RV）、信噪比（SNR）、矩（人数）和地点。将头部重新定位为更靠近传感器导致中外侧偶极坐标位置显著偏移，伴随着SNR显著增加，偶极RV降低，ECD置信体积的大小减小。结论：我们得出结论，对于临床儿科测量的SEF，重新定位头部，以尽量减少预期的SEF源位置和传感器阵列之间的距离，将显着改善SEF源测量和伴随的ECD源建模。这些问题与涉及健康或临床人群的所有儿科MEG设置相关，并强调了未来开发专门为儿科人群设计的MEG头盔的必要性。(c)2008年国际临床神经生理学联合会。由Elsevier爱尔兰有限公司出版。保留所有权利。
Objective: At present, whole-head MEG systems are designed to accommodate adult heads, thereby introducing a technical issue unique to pediatric MEG. It is known that magnetic field strength decreases as a function of 1/distance(2). For pediatric patients, we questioned whether re-positioning the head to minimize the distance between the expected source location and the MEG sensor array would significantly improve source measurement.Methods: Somatosensory-evoked fields (SEFs) were recorded in 17 children (mean = 4.96 years) with their head placed centrally in the MEG, and then re-positioned laterally to reduce the distance between the cortical source and sensors. Equivalent current dipole (ECD) source models were evaluated for changes in residual variance (RV), signal-to-noise ratio (SNR), moment (strength), and location.Results: Re-positioning the head closer to the sensors resulted in a significant shift in the mediolateral dipole coordinate location, accompanied by a significant increase in the SNR, decrease in the dipole RV, and a reduction in size of ECD confidence volumes.Conclusions: We conclude that for clinical pediatric measurement of the SEF, repositioning of the head to minimize the distance between the expected SEF source location and the sensor array will significantly improve SEF source measurement and concomitant ECD source modeling.Significance: These issues are relevant to all pediatric MEG settings involving healthy or clinical populations and underscores the need for future development of a MEG helmet specifically designed for pediatric populations. (c) 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.