Development of the noninvasive brain function diagnostic procedure using magnetoencephalography for the purpose of foreseeing the onset of cerebral ischemia

脑磁图与脑电图的临床研究我们对25例脑血管疾病进行了015气相PET（测量脑血流量（CBF）和氧提取分数（OEF））和脑磁图（测量诱发磁场）检测。此外，我们测量了大脑的自发磁场，并使用空间滤波技术（波束前）分析了频率。结果表明，N20m的偶极矩与OEF存在相关性。在缺血区，Beam former的活性分别为0和6。特别是0活动相关的OEF增加病变。MEGWe的基础研究开发了SQUID九通道磁敏计阵列，将其集成在硅芯片上，用于小动物的磁场测量。（传感器阵列有9个2.5mm (I) SQUID磁力计，每2.75mm排列成3 X 3矩阵的形状，总尺寸为10 X 10mm。）我们把这个磁力计放在一个小的屏蔽箱里，屏蔽箱放在一个屏蔽室里。该仪器可重复性地测量大鼠脑的视觉诱发场和听觉诱发场，但不能检测躯体感觉诱发场。PET的基础研究我们建立大鼠脑缺血模型，用微PET测定碳水化合物代谢。对大脑中动脉小块缺血区PET图像与x线自显像进行比较，PET能充分显示其病变。我们通过电刺激周围神经来测量脑葡萄糖代谢，但无法检测到明显的变化。然而，该病变在放射自显像上清晰可见。认为在定量评价方面，微PET对大鼠脑的分析存在局限性。

Clinical researches of MEG and PETWe performed 015 gas PET, which measured cerebral blood flow(CBF) and oxygen extraction fraction(OEF), and magnetoencephalography which measured evoked magnetic field for cerebrovascular disorder 25 examples. Furthermore, we measured spontaneous magnetic field of brain and analyzed the frequency using spatial filter technique(beam former). The results showed correlation of dipole moment of N20m and OEF. Beam former showed 0 and 6 activity in the ischemic area. Especialy, 0 activity correlated OEF increased lesion.Fundamental researches of MEGWe developed SQUID magneto meter array of nine channels which did integration on a silicon chip for the purpose of small animal's magnetic field. (the sensor array have nine 2.5mm (I) SQUID magneto meters arranged in the shape of 3 X 3 matrices every 2.75mm, and total size is 10 X 10mm.). We set this magnetometor in small shield box which set in a shield room. We could reproducibility measure visual evoked field and auditory evoked field of rat brain using this instrument, but could not detect somatosensory evoked field.Fundamental researches of PETWe made a cerebral ischemia model of rat brain and measured carbohydrate metabolism using micro PET. We compared PET image with autoradiograph in small ischemic area of middle cerebral artery, and PET could enough detect its lesion. We measured brain glucose metabolism by electric stimulation of peripheral nerve, but were not able to detect clear change. However, the lesion was depicted in autoradiograph distinctly. It is thought that there is limitation for analysis of rat brain in micro PET with an aspect of quantitative evaluation..