Advancing MRI & MRS Technologies for Studying Human Brain Function and Energetics

 描述（由申请人提供）：磁共振（MR）成像（MRI）和体内MR波谱（MRS）技术已成为大脑结构、功能、连接性、神经化学和神经能量学成像以及研究神经系统疾病的不可或缺的工具。然而，即使使用最先进的技术，实现足以解决基本的和具有挑战性的神经科学问题的上级的MRI/MRS检测灵敏度、空间和时间成像分辨率仍然是一个挑战。用于改善MRI/MRS性能的流行范例在很大程度上要求增加磁场强度，由于许多技术和安全性（即，高比吸收率（SAR））的问题，以及增加接收器通道计数，由于减小尺寸的线圈的噪声特性，这也最终受到限制。为了缓解这些主要限制，这项R24提案依靠两个机构的跨学科研究工作和领先专家的专业知识，开创了一种完全创新的工程解决方案，该解决方案使用超高介电常数（uHDC）材料与超高场MRI/MRS技术相结合，以协同提高信噪比，同时降低RF功率需求，并且用于在空间/时间分辨率上实现超过当前最先进的MR技术的前所未有的改进。 我们将使用7特斯拉（T）和10.5T全身人体扫描仪开发和优化用于人脑研究的uHDC材料原型。此外，我们将开发和评估创新的uHDC-MR技术在尖端神经科学研究中的新用途和能力。一项试点研究是在人类视觉皮层的列和皮质层水平上的神经回路和静息状态连接的功能映射，使用7 T的1H空间分辨率MRI，辅以来自纤维束成像的扩散加权图像的解剖连接。另一种是将联合收割机技术与新开发的在体31 P和17 O MRS技术相结合，无创、可靠地成像人脑在静息和激活状态下的耗氧量和ATP代谢率、脑血流量、氧提取分数和烟酰胺腺嘌呤二核苷酸（NAD）氧化还原状态。拟议的研究将把目前的神经成像开发范式转向一种高效、经济的工程解决方案，该解决方案将从uHDC和MRI领域获得倍增收益，并导致下一代MRI/MRS技术和仪器。这一进步将加速人脑成像和神经科学研究，超越现有技术所能达到的水平，促进新的研究方向，并改变我们对人脑功能和功能障碍的理解。

 DESCRIPTION (provided by applicant): Magnetic resonance (MR) imaging (MRI) and in vivo MR spectroscopy (MRS) techniques have become indispensable tools for imaging brain structure, function, connectivity, neurochemistry and neuroenergetics, and for investigating neurological disorders. However, it remains a challenge to achieve superior MRI/MRS detection sensitivity, spatial and temporal imaging resolutions adequate for addressing fundamental and challenging neuroscience questions even with the most advanced technology. The prevailing paradigms for improving MRI/MRS performance largely invoke increasing the magnetic field strength, which may have reached practically achievable limits for human studies due to many technological and safety (i.e., high specific absorption rate (SAR)) concerns, and increasing the receiver channel count which is also ultimately limited due to noise characteristics of coils of decreasing size. To alleviate these major limitations, this R24 proposal relies on the interdisciplinary research efforts and expertise of leading experts across two institutions to pioneer an entirely innovative engineering solution that uses the ultra-high dielectric constant (uHDC) material incorporated with ultrahigh-field MRI/MRS techniques for synergistically increase signal-to-noise ratio and concurrently reduce RF power demand, and for achieving unprecedented improvements in spatial/temporal resolution over the current state-of-the-art MR technologies. We will develop and optimize prototypes of uHDC material for human brain studies using 7 Tesla (T) and 10.5T whole-body human scanners. Moreover, we will exploit and assess the new utility and capability of the innovative uHDC-MR technology for cutting-edge neuroscience research. One pilot study is the functional mapping of neural circuits and resting-state connectivity at the level of columns and cortical layers in the human visual cortex with ultrahigh spatial resolution 1H MRI at 7T, complemented with anatomical connectivity derived from diffusion weighted images for tractography. The other one is to combine the uHDC technique with newly developed in vivo 31P and 17O MRS techniques for noninvasively and reliably imaging the cerebral metabolic rates of oxygen consumption and ATP, cerebral blood flow, oxygen extraction fraction and nicotinamide adenine dinucleotide (NAD) redox state in the human brain at resting and activated states. The proposed research will shift the current paradigm of neuroimaging development towards an efficient, cost-effective engineering solution that will attain multiplicative gains from uHDC and ultrahigh fields, and lead to next generation o MRI/MRS technology and instrument. Such advancement will accelerate human brain imaging and neuroscience research beyond what can be achieved through existing technology, promote new research directions, and transform our understanding regarding the human brain function and dysfunction.