Highly Efficient MRI Pulse Sequences for High Resolution Physiological and Functional Brain Imaging

总结 该项目将开发具有更高空间和时间分辨率、更大脑容量的MRI生理成像， 覆盖范围和更快的加速脉冲序列。生理图像具有微血管对比度- 加权血氧水平依赖性（BOLD）、脑血流量（CBF）和脑血容量（CBV）。 重要的是，待开发的技术在很大程度上对静脉血对信号的贡献不敏感， 与传统的BOLD回波平面成像（EPI）序列不同， 神经系统疾病的生理标志物成像和皮质层fMRI的更高特异性， 从而在人类神经回路成像中实现更高的粒度。每个脉冲的新加速技术 序列将被纳入，以增加切片体积覆盖范围，提高信噪比（SNR）， 点扩散函数（PSF）在信号定位中的应用。序列开发和评价将在 多个3 T和7 T成像部位。我们将开发一个软件包与先进的变种几个脉冲 序列：缩放的3D梯度和自旋回波（GRASE），用于CBF成像的动脉自旋标记（ASL），切片- 用于CBV成像的饱和平板反转血管空间占用（SS-SI-VASO），以及新型VASO 采用“全局激励循环多次采集”（MAGEC）-VASO技术实现全脑 覆盖该软件包还将包括一个模块化的分析管道，供神经科学家使用， 医生无需广泛的MR物理或编码专业知识。实现无创成像， 人类大脑中的神经元回路将使神经科学家能够研究正常的大脑过程， 医学科学家研究神经系统的变化和神经系统疾病。目前，高分辨率功能磁共振成像 这项技术可以用来识别不同皮层深度神经活动的功能磁共振成像，但受到严重限制， 皮质静脉引流的局部信号不佳。该项目创新了新的，强大的3D fMRI成像 消除静脉污染的序列，从而提供精细尺度神经元的高保真映射， 与当前梯度回波EPI BOLD成像相比，

Summary This project will develop MRI physiological imaging with higher spatial and temporal resolution, larger brain coverage, and faster accelerated pulse sequences. The physiologic images have contrasts of microvascular- weighted blood oxygen level dependent (BOLD), cerebral blood flow (CBF) and cerebral blood volume (CBV). Importantly, the techniques to be developed are largely insensitive to venous blood contributions to signal, unlike traditional BOLD echo planar imaging (EPI) sequences, and thus they are extremely useful for precision imaging of physiological markers in neurological disorders and for higher specificity in cortical layer fMRI, enabling higher granularity in human neurocircuitry imaging. Novel acceleration techniques for each pulse sequence will be incorporated to increase slice-volume coverage and improve signal to noise ratio (SNR) and point spread function (PSF) in signal localization. Sequence development and evaluations will be performed at several 3T and 7T imaging sites. We will develop a software package with advanced variants of several pulse sequences: zoomed 3D gradient-and-spin-echo (GRASE), arterial spin labeling (ASL) for CBF imaging, slice- saturation slab- inversion vascular space occupancy (SS-SI-VASO) for CBV imaging, and the novel VASO technique with “multiple acquisitions with global excitation cycling” (MAGEC)-VASO to achieve whole brain coverage. The software package will also include a modular analysis pipeline for use by neuroscientists and physicians without the need for extensive MR-physics or coding expertise. Achieving non-invasive imaging of neuronal circuits in the human brain will allow neuroscientists to study normal brain processes and allow medical scientists to study neurocircuitry changes and neurological diseases. Currently, high-resolution fMRI technology could be used to identify fMRI of neural activity at different cortical depths, but is severely limited by poorly localized signal from venous drainage in the cortex. This project innovates new, robust 3D fMRI imaging sequences that eliminate venous contamination, thus affording high fidelity mapping of fine-scale neuronal circuitry compared to current gradient echo EPI BOLD imaging.