使用单回声EPI和读出反转的第一图像 (REFILL) 改进了fMRI的动态扭曲校正
Simon Daniel Robinson1,2,3,4, Beata Bachrata3,4,5, Korbinian Eckstein3
1Centre of Advanced Imaging, University of Queensland, Brisbane, Australia.
Human brain mapping
|August 7, 2023
概括
我们开发了一种新的功能性MRI (fMRI) 动态扭曲校正方法,称为REFILL. 这种方法提高了信号噪声比,并消除了人工物,使实时校正成为常规使用的可行性.
科学领域:
- 磁共振成像技术 磁共振成像技术
- 神经成像是一种神经成像.
- 生物物理学的生物物理.
背景情况:
- 磁场不均性在MRI扫描仪中是由组织敏感性差异引起的,由于生理运动和系统不稳定性而波动.
- 这些动态场变化引入了fMRI数据的扭曲,使分析复杂化.
- 现有的校正方法通常需要复杂,耗时或易出错的技术,如多回声扫描或相解封.
研究的目的:
- 引入和验证一种新的fMRI动态扭曲校正方法,这种方法是强大的,高效的,适合实时实施.
- 通过减轻运动和呼吸引起的场波动来提高fMRI数据的准确性和可靠性.
主要方法:
- 拟议的方法,反编码第一图像和低分辨率参考扫描 (REFILL),使用单回声EPI数据和短 (3-10s) 三重回声参考扫描.
- 它在没有相解封的情况下计算相位偏移,并从反向读出EPI体积中进行校正.
- 该方法是为了计算的简单性和稳定性而设计的,使得扫描仪上的处理成为可能.
主要成果:
- 即使在7T时,REFILL也能准确地测量由闪光变化,运动和呼吸引起的动态B0场变化.
- 与静态校正方法相比,它实现了时间序列信号噪声比率>20%的增加.
- 使用REFILL处理的fMRI数据没有使用静态场映射观察到的与刺激相关的扭曲工件.
结论:
- 在fMRI的动态扭曲校正中,REFILL提供了显著的进步,克服了以前方法的局限性.
- 它的稳定性,速度和准确性使fMRI中的常规动态扭曲校正成为可能.
- 该方法提高了数据质量和可靠性,特别是在具有挑战性的成像条件下,如高场强度 (7T).
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