Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany.
Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany.
Neuroimage. 2018 Oct 15;180(Pt B):547-558. doi: 10.1016/j.neuroimage.2017.08.029. Epub 2017 Aug 10.
The development of highly accelerated fMRI acquisition techniques has led to novel possibilities to monitor cerebral activity non-invasively and with unprecedented temporal resolutions. With the emergence of dynamic connectivity and its ability to provide a much richer characterization of brain function compared to static measures, fast fMRI may yet play a crucial role in tracking dynamically varying networks. In spite of the dominance of slow hemodynamic contributions to the BOLD signal, high temporal sampling rates nevertheless improve the measurement of physiological noise, yielding an exceptional sensitivity for the detection of periods of transient connectivity at time scales of a few tens of seconds. There is also evidence that relevant BOLD fluctuations are detectable at high frequencies, implying that the benefits of fast fMRI extend beyond the ability to sample nuisance confounds. Here we review the latest technological advancements that have established fast fMRI as an effective acquisition technique, as well as its current and future implications on the analysis of dynamic networks.
高度加速 fMRI 采集技术的发展为非侵入式和具有前所未有的时间分辨率监测大脑活动提供了新的可能性。随着动态连接的出现及其相对于静态测量提供更丰富的大脑功能描述的能力，快速 fMRI 可能在跟踪动态变化的网络方面发挥关键作用。尽管慢血流动力学对 BOLD 信号的贡献占主导地位，但高时间采样率仍可改善生理噪声的测量，从而在几十秒的时间尺度上对瞬态连接的时间段具有极高的检测灵敏度。也有证据表明，在高频下可以检测到相关的 BOLD 波动，这意味着快速 fMRI 的优势不仅在于能够采样干扰性混杂因素。本文综述了最新的技术进展，这些进展将快速 fMRI 确立为一种有效的采集技术，以及它对动态网络分析的当前和未来影响。
