Takanashi Y
Department of Neurology and Gerontology, Kyoto Prefectural University of Medicine.
Rinsho Byori. 1993 Nov;41(11):1191-7.
This review attempts to provide the basis of neuromagnetism and its clinical applications. The progress in this field has been connected with the introduction of SQUID (superconducting quantum interference device) magnetometer which was produced by the progress of low temperature physics. A magnetic field is generated by an electric current in accordance with 'the right hand law', and the magnetic field pattern inevitably crosses orthogonally that of the electric field. A SQUID magnetometer is able to only detect the magnetic field which is generated by the current dipole orientated parallel to the skull surface. Magnetoencephalography (MEG) has several advantages compared to electroencephalography (EEG). One is its more excellent spatial resolution than that of EEG, and the other is a non-contact measurement, i. e., a noninvasive method. Therefore, MEG measurement could not interfere with sweating on the skull skin or a depolarization between skin and electrodes. This advantage allows it to record the magnetic field generated by the direct current potential in the cortical surface, and one example, that is, direct current magnetic fields evoked by slow potential changes in rat brain during asphyxia, are shown.
本综述旨在提供神经磁学及其临床应用的基础。该领域的进展与低温物理学的发展所催生的超导量子干涉装置（SQUID）磁力计的引入相关。根据“右手定律”，电流会产生磁场，且磁场模式不可避免地与电场模式正交。SQUID磁力计只能检测由平行于颅骨表面定向的电流偶极产生的磁场。与脑电图（EEG）相比，脑磁图（MEG）具有多个优势。其一，它的空间分辨率比EEG更出色；其二，它是一种非接触式测量，即非侵入性方法。因此，MEG测量不会干扰颅骨皮肤出汗或皮肤与电极之间的去极化。这一优势使其能够记录皮质表面直流电位产生的磁场，并展示了一个例子，即大鼠脑在窒息期间由缓慢电位变化诱发的直流磁场。
