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

摘要 该项目将开发具有更高空间和时间分辨率、更大大脑的MRI生理成像 覆盖范围和更快的加速脉冲序列。生理图像有微血管的对比- 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，将要开发的技术在很大程度上对静脉血液对信号的贡献不敏感， 与传统的粗体平面回波成像(EPI)序列不同，它们在精确度方面非常有用 神经疾病的生理标记物的成像和皮质层功能磁共振成像的更高特异性， 在人类神经回路成像中实现更高的粒度。针对每个脉冲的新加速技术 序列将被合并以增加切片体积覆盖并改善信噪比(SNR)和 点扩展函数在信号定位中的应用。序列开发和评估将在 几个3T和7T成像站点。我们将开发一个包含几个PULSE高级变种的软件包 序列：缩放3D梯度和自旋回波(GRASE)，用于脑血流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占位率(SS-SI-VASO)及新型VASO 基于MAGEC-VASO的全脑多点采集技术 覆盖范围。该软件包还将包括一个模块分析管道，供神经科学家和 医生，不需要广泛的磁共振物理或编码专业知识。实现非侵入性成像 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，并允许 医学科学家研究神经回路的变化和神经系统疾病。目前，高分辨率的功能磁共振成像 这项技术可以用来识别不同皮质深度的神经活动的功能磁共振成像，但受到以下严重限制 皮质静脉引流信号局部化差。该项目创新了新的、强大的3D功能磁共振成像 消除静脉污染的序列，从而提供高保真的精细神经元标测 电路对比电流梯度回波EPI大胆成像。

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.