NexGen 7T MRI scanner for mesoscale brain imaging: Integration and Dissemination

摘要 加州大学伯克利分校的“NexGen”7特斯拉核磁共振扫描仪是我们希望提供的独特资源 全球的神经科学合作。它是专门为极高分辨率而设计的 皮质板层和柱状神经回路组织尺度下的结构和功能神经成像 (“中尺度”)。为了实现这一点，NexGen扫描仪建立在现有的标准7T扫描仪和 整合了许多技术进步，创造了协同改进和速度提升， 分辨率和信号。这些进步包括：目前性能最高的独一无二的头戴式 磁梯度线圈旨在以更快的时间尺度(更高的梯度幅度)安全地产生更多信号 和无外周神经刺激的转换率；PNS)，高密度接收器阵列线圈(例如，高达128 集成到7T中的通道接收器阵列)，实现前所未有的空间分辨率和成像 加速。作为这一合作努力的一部分，我们将在脉冲序列方面创造新的进展 对于新的神经科学应用，成像利用扫描仪硬件的更高 性能。该扫描仪已在GE-EPI和可重复进行的中尺度功能磁共振研究中得到验证 Vaso功能磁共振成像的各向同性分辨率在0.39 mm到0.6 mm之间，即体积增加了4.6到23倍 在常规7T扫描仪上，fMRI的分辨率高于典型的1 mm各向同性分辨率。更强的渐变 在扩散成像方面提供了相当大的改进，通过缩短的TES达到更高的b值。这些 硬件的进步也使大脑覆盖更大的区域，更高的时间分辨率和 中尺度分辨率的扭曲。因此，有了NexGen 7T，中尺度神经科学实验可以 与传统的变焦、小体积成像方法相比有了很大的扩展。如此独一无二的 仪器具有继续推进该领域的巨大潜力，并将被不同的群体最佳使用 神经学家和临床科学家。目前U24提案的资金将促进工程 和科学人员支持和维护扫描仪的使用；实现高效的数据传输和 分析，以及国家科学合作的学科招募、用户培训和指导 国际上也是如此。虽然这个项目的主要目标是为更高的 在功能和结构的人脑研究中，研究资源还具有潜在的 更好地了解神经系统疾病，如癫痫、阿尔茨海默氏症和精神障碍。

SUMMARY The "NexGen" 7 Tesla MRI scanner at UC Berkeley is a unique resource that we wish to make available for neuroscience collaborations across the globe. It was specifically designed for extremely high resolution structural and functional neuroimaging at the scale of cortical laminae and columnar neurocircuit organization ("meso-scale"). To achieve this, the NexGen scanner builds upon existing standard 7T scanners and integrates a number of technological advances, creating synergistic improvements and gains in speed, resolution and signal. Such advances include: currently the highest performance one-of-a-kind head-only magnetic gradient coil designed to safely create more signal at faster time scales (higher gradient amplitudes and slew rates without peripheral nerve stimulation; PNS), high-density receiver array coils (e.g. up to 128 channel receive array integrated into a 7T) that enable unprecedented spatial resolution and image-forming accelerations. As part of this collaborative endeavor, we will be creating novel advances in pulse sequences for novel neuroscientific applications imaging to take advantage of the scanner hardware’s higher performance. The scanner has been validated in reproducible mesoscale fMRI studies using GE-EPI and VASO fMRI at isotropic resolutions between 0.39 mm and 0.6 mm, that is a 4.6 to 23-fold higher volumetric resolution over typical 1 mm isotropic resolution in fMRI on conventional 7T scanners. The stronger gradients offer considerable improvements in diffusion imaging reaching higher b-values with shortened TEs. These hardware advances also enable larger areas of brain coverage, higher temporal resolutions and reduced distortions at mesoscale resolutions. Thus, with the NexGen 7T, meso-scale neuroscience experiments can be greatly expanded from traditional zoomed, small volume imaging approaches. Such a one-of-a-kind instrument has great potential to continue to advance the field and will be optimally used by a diverse group of neuroscientists and clinician scientists. Funding of the current U24 proposal would facilitate engineering and scientific personnel to support and maintain the use of the scanner; enables efficient data transfer and analysis, as well as the subject recruitment, user training and guidance of scientific collaborations nationally and internationally. While the main goal of this project is to provide an innovative resource for higher granularity in functional and structural human brain research, the research resource also holds potential for better understanding neurological diseases, such as Epilepsy, Alzheimer’s and mental disorders.