Functional quantitative susceptibility mapping (fQSM)
Functional quantitative susceptibility mapping (fQSM)
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DOI：
10.1016/j.neuroimage.2014.06.011
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发表时间：
2014-10-15
期刊：
影响因子：
5.7
通讯作者：
Bowtell, Richard
中科院分区：
文献类型：
--
作者：
Balla, David Z.;Sanchez-Panchuelo, Rosa M.;Bowtell, Richard
血氧水平依赖(BOLD)功能磁共振成像(FMRI)是一种强大的技术，通常基于对复杂时间序列的幅度分量的统计分析。在这里，我们还询问了fMRI时间序列的相位数据，并使用定量磁化率映射(QSM)来研究功能性QSM(FQSM)相对于标准幅度BOLD fMRI的潜力。在单方位(SO)和多方位(MO)实验中，每隔3s采集1 mm各向同性的高空间分辨率数据，使用7T的变焦多层梯度回波EPI，后者包括4次重复，受试者的头部相对于B-0旋转。重建了幅度、相位和QSM时间序列的统计参数图(SPM)，并对每个序列进行了详细的分析。基于恰好在QSM和幅度SPM(公共体素)中被发现显着的体素的相对数量，对几个fQSM管道进行了评估和比较。我们发现，fQSM相对于震级数据的灵敏度和空间可靠性强烈依赖于SPM中定义的激活体素的任意意义阈值，以及对相位时间序列进行时空滤波的效率。敏感度和空间可靠性略取决于是否执行MO或SO fQSM，以及SO数据使用的QSM计算方法。我们的结果展示了fQSM作为一种定量方法描绘大胆变化的潜力。我们还批判性地讨论了与这项耐人寻味的新技术相关的技术挑战和问题。(C)2014 Elsevier Inc.保留所有权利。
Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a powerful technique, typically based on the statistical analysis of the magnitude component of the complex time-series. Here, we additionally interrogated the phase data of the fMRI time-series and used quantitative susceptibility mapping (QSM) in order to investigate the potential of functional QSM (fQSM) relative to standard magnitude BOLD fMRI. High spatial resolution data (1 mm isotropic) were acquired every 3 seconds using zoomed multi-slice gradient-echo EPI collected at 7 T in single orientation (SO) and multiple orientation (MO) experiments, the latter involving 4 repetitions with the subject's head rotated relative to B-0. Statistical parametric maps (SPM) were reconstructed for magnitude, phase and QSM time-series and each was subjected to detailed analysis. Several fQSM pipelines were evaluated and compared based on the relative number of voxels that were coincidentally found to be significant in QSM and magnitude SPMs (common voxels). We found that sensitivity and spatial reliability of fQSM relative to the magnitude data depended strongly on the arbitrary significance threshold defining "activated" voxels in SPMs, and on the efficiency of spatio-temporal filtering of the phase time-series. Sensitivity and spatial reliability depended slightly on whether MO or SO fQSM was performed and on the QSM calculation approach used for SO data. Our results present the potential of fQSM as a quantitative method of mapping BOLD changes. We also critically discuss the technical challenges and issues linked to this intriguing new technique. (C) 2014 Elsevier Inc. All rights reserved.