Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
QuSpin Inc., Louisville, Colorado, USA.
Ann N Y Acad Sci. 2022 Nov;1517(1):107-124. doi: 10.1111/nyas.14890. Epub 2022 Sep 5.
Magnetoencephalography (MEG) measures the small magnetic fields generated by current flow in neural networks, providing a noninvasive metric of brain function. MEG is well established as a powerful neuroscientific and clinical tool. However, current instrumentation is hampered by cumbersome cryogenic field-sensing technologies. In contrast, MEG using optically pumped magnetometers (OPM-MEG) employs small, lightweight, noncryogenic sensors that provide data with higher sensitivity and spatial resolution, a natural scanning environment (including participant movement), and adaptability to any age. However, OPM-MEG is new and the optimum way to design a system is unknown. Here, we construct a novel, 90-channel triaxial OPM-MEG system and use it to map motor function during a naturalistic handwriting task. Results show that high-precision magnetic field control reduced background fields to ∼200 pT, enabling free participant movement. Our triaxial array offered twice the total measured signal and better interference rejection compared to a conventional (single-axis) design. We mapped neural oscillatory activity to the sensorimotor network, demonstrating significant differences in motor network activity and connectivity for left-handed versus right-handed handwriting. Repeatability across scans showed that we can map electrophysiological activity with an accuracy ∼4 mm. Overall, our study introduces a novel triaxial OPM-MEG design and confirms its potential for high-performance functional neuroimaging.
脑磁图（MEG）测量神经网络中电流产生的小磁场，提供大脑功能的非侵入性度量。MEG 已被确立为一种强大的神经科学和临床工具。然而，当前的仪器设备受到繁琐的低温场感应技术的限制。相比之下，使用光泵磁强计（OPM-MEG）的 MEG 采用小型、轻量级、非低温的传感器，提供更高灵敏度和空间分辨率的数据、自然扫描环境（包括参与者运动）以及对任何年龄段的适应性。然而，OPM-MEG 是新的，设计系统的最佳方法尚不清楚。在这里，我们构建了一种新型的 90 通道三轴 OPM-MEG 系统，并使用它来绘制自然书写任务期间的运动功能。结果表明，高精度磁场控制将背景场降低到约 200 pT，从而实现了参与者的自由运动。与传统（单轴）设计相比，我们的三轴阵列提供了两倍的总测量信号和更好的干扰抑制。我们将神经振荡活动映射到感觉运动网络，证明了左手和右手书写时运动网络活动和连接的显著差异。扫描之间的可重复性表明，我们可以以约 4 毫米的精度绘制电生理活动。总的来说，我们的研究介绍了一种新型的三轴 OPM-MEG 设计，并证实了其在高性能功能神经成像中的潜力。
