Development of Layer Specific FMRI for Clinical Scanners

摘要 层特异性功能磁共振成像是一种新的、令人兴奋的非侵入性探测中尺度脑网络的工具， 无需侵入性外科手术，如电极植入或共聚焦 显微镜。最近的研究表明，特定层级的功能磁共振成像可以识别 柱状，以及网络层特定的结构。而层特异性功能磁共振成像领域 虽然以超高场核磁共振扫描仪(7T及以上)为主，但仍极具挑战性 要在3T扫描仪中实现这些结果，因为它们的信噪比(SNR)更低。这个 对超高场扫描仪的需求源于对层的极小体素的要求 特定的功能磁共振成像，这转化为信噪比的戏剧性损失。 这种对超高场扫描仪的需求意味着，许多超高场扫描仪必须在小范围内进行 动物，而人类在这一领域的工作仅限于少数几个选定的机构。这样做的目的是 建议是开发所需的技术，使层特异性功能磁共振成像在3T扫描仪上可行， 在大多数研究机构中很常见。我们建议的策略是提高SNR效率和 通过使用缩小的视场、3D读出和新的正片来缩短扫描时间 基于速度选择性脉搏的血管造影术采集动脉血 体积加权图像的速度快得多。同时，我们还将致力于降低 通过一种有效的回波校正技术进行测量。

Summary Layer Specific FMRI is a new and exciting tool to probe mesoscale brain networks non-invasively, without the need for invasive surgical procedures, such as electrode implantation, or confocal microscopy. Recent work has demonstrated the Layer Specific FMRI can identify both the columnar, as well as layer specific structure of a network. While the field of Layer Specific FMRI is dominated by “ultra-high” field MRI scanners (7T and above), it is still extremely challenging to achieve those results in 3T scanners because of their reduced signal:noise ratio (SNR). The need for ultra-high field scanners stems from the requirement of extremely small voxels for layer specific FMRI, which translates into a dramatic loss of SNR. This need for ultra high field scanners means that much of it has to be carried out on small animals, and human work in this area is limited to a few select institutions. The goal of this proposal is to develop the technology needed to make layer specific FMRI feasible at 3T scanners, common in most research institutions. Our proposed strategy is to improve SNR efficiency and reduce scan time by using a reduced field of view, 3D read-out in tandem with a new positive vascular contrast imaging method based on Velocity Selective pulses to collect arterial blood volume weighted images much faster. At the same time, we will also aim to reduce the noise of the measurement by an efficient echo correction technique.