High-Speed fMRI of Resting State Connectivity

描述（由申请人提供）：使用静息状态fMRI的功能连接组学是一种快速扩展的无任务方法，预计将产生重大的临床影响。最近的研究已经发现了100多个静息状态网络（RSNs），它们表现出相当大的时间和空间非平稳性。与传统的静息状态功能磁共振成像相比，现在有相当大的兴趣在更高频率（高达5hz）下表征静息状态连接。然而，扫描内连接的非静止性和头部运动伪影损害了检测单个受试者rsn的灵敏度。功能磁共振成像方法的进步提高了数据采集率，在提高基于任务的功能磁共振成像的BOLD灵敏度和绘制大脑状态的时间动态方面发挥了重要作用。提高采样率可以改善静息状态信号波动和心脏相关信号脉动的分离，正如我们的初步数据所显示的那样，脉动波形在大脑皮层区域之间存在相当大的区域差异。然而，高速fMRI在高加速速率下存在重建伪影，并且尚未研究使用多回波采集来分离BOLD和非BOLD信号源。本研究的长期目标是开发一种可靠和敏感的静息状态fMRI方法，用于神经系统疾病患者的有效脑区域的术前测绘。本文的目标是将同步多层（SMS） EPI和多层回声体成像（EVI）结合起来，在不牺牲图像质量的前提下，实现前所未有的时空分辨率和BOLD灵敏度，这两种方法已经成为主要的高速数据采集方法与多维压缩感知相结合。我们还将对运动伪影进行综合校正。该方法将在健康对照和脑肿瘤患者中进行验证，使用时间动态统计分析方法灵敏地捕捉静息状态波动的时间动态。这项研究的基本原理是静息状态功能磁共振成像有可能取代基于任务的功能磁共振成像来绘制主要的大脑网络，这将降低成本，并使功能磁共振成像能够用于无法使用基于任务的功能磁共振成像研究的患者群体。虽然静息状态fMRI的功能定位已被证明与基于任务的fMRI一致，但在单个受试者水平上，需要提高静息状态fMRI的可靠性。这项研究将建立超高速功能磁共振成像作为一种敏感和定量的方法来绘制临床和神经科学研究中个体受试者的静息状态连接。表征静息状态连通性的时间动态将增强我们对静息状态下大脑内在活动的理解，从而提高诊断和指导治疗。这

DESCRIPTION (provided by applicant): Functional connectomics using resting state fMRI is a rapidly expanding task-free approach, which is expected to have significant clinical impact. Recent studies have demonstrated more than 100 resting state networks (RSNs), which exhibit considerable temporal and spatial non-stationary. There is now considerable interest in characterizing resting state connectivity at much higher frequencies (up to 5 Hz) than detectable with traditional resting state fMRI. However, intra-scan non-stationary of connectivity and head movement artifacts compromise the sensitivity of detecting RSNs in single subjects. Advances in fMRI methodology to increase data acquisition rates have played an important role in improving BOLD sensitivity for task-based fMRI and for mapping the temporal dynamics of brain-states. Increasing the sampling rate improves segregation of resting state signal fluctuation and cardiac-related signal pulsation, which as our preliminary data show exhibits considerable regional differences of the pulsation waveform across cortical brain regions. However, high-speed fMRI suffers from reconstruction artifacts at high acceleration rates, and adding multi-echo acquisition to separate BOLD and non-BOLD signal sources has not been investigated. The long-term goal of this research is to develop a reliable and sensitive resting state fMRI method for presurgical mapping of eloquent brain regions in patients with neurological disorders. The objective of this proposal is to integrate simultaneous multi-slice (SMS) EPI and multi-slab echo-volumar imaging (EVI), which have emerged as the principal high-speed data acquisition approaches with multi-dimensional compressed sensing, to achieve unprecedented temporal and spatial resolution and BOLD sensitivity without sacrificing image quality. We will additionally integrate a comprehensive correction of motion artifacts. This approach will be validated in healthy controls and patients with brain tumors using time-dynamic statistical analysis methods to sensitively capture the temporal dynamics of resting state fluctuations. The rationale of this research is that resting state fMRI has the potential to replac task-based fMRI for mapping major brain networks, which would reduce costs and enable fMRI in patient groups that cannot be studied with task-based fMRI. While functional localization of resting state fMRI across groups of subjects has been demonstrated to be consistent with task-based fMRI, there is a need to improve reliability of resting state fMRI at the single subject leve. This research will establish ultra-high-speed fMRI as a sensitive and quantitative approach for mapping resting state connectivity in individual subjects in clinical and neuroscience research. Characterizing the temporal dynamics of resting state connectivity will enhance our understanding of intrinsic brain activity at rest to improve diagnostics and to guide therapy. This will ultimately lead to improved individualized treatment strategies and prognosis based upon patient specific functional brain mapping.