Direct MEG/EEG detection using a novel MRI approach

使用新型 MRI 方法进行直接 MEG/EEG 检测

• 批准号: 9566019
• 负责人: PAUL A BOTTOMLEY
• 金额: $ 24.56万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-30 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9566019
• 关键词: Acceleration; Area; Autistic Disorder; BRAIN initiative; Blood; Brain; Cardiac; Cell Culture Techniques; Clinical; Craniocerebral Trauma; Data; Dementia; Detection; Development; Echo-Planar Imaging; Electrocardiogram; Electrodes; Electroencephalography; Electrophysiology (science); Environment; Epilepsy; Evoked Potentials; Fiber; Fourier Transform; Frequencies; Functional Magnetic Resonance Imaging; Goals; Grant; Human; Human Volunteers; Image; Linear Algebra; Link; Magnetic Resonance Imaging; Magnetism; Magnetoencephalography; Measures; Mental Depression; Methods; Modeling; Morphologic artifacts; Nervous system structure; Neurons; Noise; Operative Surgical Procedures; Oxygen; Phase; Physiologic pulse; Physiological; Play; Relaxation; Research; Resolution; Rest; Scalp structure; Scheme; Series; Signal Transduction; Sister; Source; Spectrum Analysis; Speed; Stroke; Sum; Technology; Testing; Time; Tissues; Trauma; United States National Institutes of Health; Visual; Water; base; brain electrical activity; brain tissue; brain volume; clinical Diagnosis; clinical diagnostics; cognitive function; cohort; cranium; density; detector; electrical measurement; imaging approach; imaging detection; imaging modality; innovative technologies; magnetic field; meetings; neurotransmission; novel; novel strategies; relating to nervous system; simulation; superconducting quantum interference device; tool; volunteer

This R21 grant responds to RFA-EY-17-001 “BRAIN Initiative: New Concepts and Early-Stage Research for Large-Scale Recording and Modulation in the Nervous System …for unique and innovative technologies in an even earlier stage of development … including new and untested ideas in the initial stages of conceptualization… where preliminary data would not be available”. Electroencephalography (EEG) and magnetoencephalography (MEG) which measures the magnetic fields associated with the neuronal currents are the only tools currently available to noninvasively measure electrical activity in human brain. They provide a wealth of information on brain electrical activity in epilepsy, dementias, autism, depression, stroke, and trauma for clinical diagnosis and surgical planning. Yet the neuronal currents detected by EEG electrodes are confounded by intervening brain, CSF, skull and scalp tissues, while MEG requires superconducting magnetometers and a quiet magnetic environment. Moreover, the signal sources in EEG and MEG are not spatially-encoded per se and pose an inverse problem without a unique solution. While magnetic resonance imaging (MRI) plays a key role in The Brain Initiative with fiber track mapping and functional MRI (fMRI) methods and it aught to be sensitive to EEG/MEG signals, attempts to use MRI to measure neuronal electrical activity have thus far proved inconclusive or null. The MEG signals range from 10-15 to 10-12 Tesla(T) during epileptic spikes, while MRI’s sensitivity to neuronal sources is estimated at only about 10-10 T. Support is sought to develop an entirely new MRI approach to directly measure MEG-modulated MRI signals using a spatial encoding scheme that provides exceptionally high intrinsic signal-to-noise ratios (SNR) and speed. The new method of localization–spectroscopy with linear algebraic modeling or SLAM–uses a greatly-reduced SNR-optimized gradient encoding set to directly localize signals from small volumes of brain tissue that can be arbitrarily segmented and resized post-acquisition, from scout MRI. Tests show that SLAM can deliver an SNR of ≈105, yielding a calculated sensitivity of 10-14-10-15T for the brain water signal in ~10ml volumes in ~30ms acquisitions (~30Hz bandwidth). Mechanistically, MEG/EEG modulation of MRI signals arises via the zero/low-frequency dipole-dipole component of the spectral density function, which is directly proportional to the spin-spin relaxation rate, 1/T2. The plan is to continuously apply T2-sensitive SLAM MRI at ~30 Hz to detect MEG/EEG modulations of ~10-14T signals over a meaningful ~30Hz EEG range in healthy human volunteers. Simultaneous MRI-compatible EEG will be used for reference to identify signals, detect artifacts and optimize detection of relevant signals. Studies to detect resting-state, visual- and audio-evoked potentials are planned. If successful, the grant would deliver noninvasive MRI-based localization and sizing of neuronal signal sources which might then be correlated directly with fMRI, fiber-tracking and other MRI metrics.

R21对RFA-EY-17-001的回应“大脑倡议：新概念和早期研究 神经系统中的大规模记录和调制……用于独特而创新的技术 即使是早期的发展阶段……包括概念化的最初阶段中的新的和未经测试的想法…… 初步数据将无法获得”。脑电图（EEG）和磁脑摄影 （MEG）测量与神经元电流相关的磁场是唯一的工具 目前可用于无创测量人脑的电活动。他们提供大量信息 关于癫痫，痴呆症，自闭症，抑郁，中风和创伤的脑电活动 诊断和手术计划。然而，脑电电极检测到的神经元电流被混淆 干预大脑，CSF，头骨和头皮组织，而MEG需要超导磁力计和A 安静的磁环境。此外，脑电图和MEG中的信号源本身不是空间编码的 并在没有独特解决方案的情况下构成一个反问题。而磁共振成像（MRI）扮演钥匙 通过纤维轨道映射和功能性MRI（fMRI）方法在大脑倡议中的作用，并且年龄 对EEG/MEG信号敏感，尝试使用MRI测量神经元电活动的尝试已经到目前为止 经过证明的尚无定论或无效。 MEG信号在癫痫峰值期间的10-15至10-12 Tesla（T），而 MRI对神经元来源的敏感性仅为10-10 t。 感觉到支持以开发一种全新的MRI方法，以直接测量MEG调制的MRI 使用空间编码方案的信号，该方案提供了异常高的固有信噪比（SNR） 和速度。带有线性代数建模或SLAM的定位 - 光谱的新方法 - 大量降低了SNR优化的梯度编码集，以直接定位来自少量大脑的信号 从Scout MRI进行任意分割和调整大小的组织。测试表明大满贯 可以输送≈105的SNR，在〜10mL中对脑水信号的计算灵敏度为10-14-10-15T 大约30ms的收购（〜30Hz带宽）的卷。机械上，MEG/EEG MRI信号调制 通过光谱密度函数的零/低频偶极 - 偶极偶极组成分产生，直接 与自旋旋转松弛率成正比1/t2。该计划是连续应用T2敏感的SLAM MRI 〜30 Hz检测在健康中有意义的〜30 Hz EEG范围内〜10-14T信号的MEG/EEG调制 人类志愿者。同时使用MRI兼容的EEG将用于参考以识别信号，检测 伪像并优化相关信号的检测。检测静止状态，视觉和音频诱发的研究 计划的潜力。如果成功，赠款将提供非侵入性MRI的本地化和规模 然后，神经元信号源可能直接与fMRI，纤维跟踪和其他MRI指标直接相关。