目的:各种神经影像学技术的探索已成为神经科学研究领域的重点。基于光泵浦磁力计(OPM-MEG)的脑磁图已显示出成为下一代功能神经成像的巨大潜力,具有高信号强度和灵活的传感器布置的优点。在这项研究中,我们构建了一个31通道的OPM-MEG系统,并初步比较了OPM-MEG测量的磁响应与功能磁共振成像(fMRI)在抓取任务期间检测到的血氧水平相关信号之间的时空关系.
方法:对于OPM-MEG,β波段(15-30Hz)振荡活动可以在多个受试者和多个会话运行中可靠地检测到。为了有效地定位抑制性振荡活动,提出了一种基于源功率谱比的成像方法。这种方法与传统的源成像方法进行了比较,如最小范数类型和波束形成器方法,并应用于OPM-MEG源分析。随后,分析了OPM-MEG和fMRI在源水平的空间和时间响应。
结果:与基准方法相比,通过仿真证实了所提出方法的有效性。我们的演示显示,四个受试者的OPM-MEG和fMRI定位结果之间的平均空间间隔为10.57±4.41mm。此外,fMRI约束的OPM-MEG定位结果表明成像范围更集中.
结论:综合来看,OPM-MEG表现出的性能将其定位为功能性手术评估的潜在工具.
OBJECTIVE: The exploration of various neuroimaging techniques have become focal points within the field of neuroscience research. Magnetoencephalography based on optically pumped magnetometers (OPM-MEG) has shown significant potential to be the next generation of functional neuroimaging with the advantages of high signal intensity and flexible sensor arrangement. In this study, we constructed a 31-channel OPM-MEG system and performed a preliminary comparison of the temporal and spatial relationship between magnetic responses measured by OPM-MEG and blood-oxygen-level-dependent signals detected by functional magnetic resonance imaging (fMRI) during a grasping task.
METHODS: For OPM-MEG, the β-band (15-30 Hz) oscillatory activities can be reliably detected across multiple subjects and multiple session runs. To effectively localize the inhibitory oscillatory activities, a source power-spectrum ratio-based imaging method was proposed. This approach was compared with conventional source imaging methods, such as minimum norm-type and beamformer methods, and was applied in OPM-MEG source analysis. Subsequently, the spatial and temporal responses at the source-level between OPM-MEG and fMRI were analyzed.
RESULTS: The effectiveness of the proposed method was confirmed through simulations compared to benchmark methods. Our demonstration revealed an average spatial separation of 10.57 ± 4.41 mm between the localization results of OPM-MEG and fMRI across four subjects. Furthermore, the fMRI-constrained OPM-MEG localization results indicated a more focused imaging extent.
CONCLUSIONS: Taken together, the performance exhibited by OPM-MEG positions it as a potential instrument for functional surgery assessment.