Effect of phase-encoding direction on group analysis of resting-state functional magnetic resonance imaging
Effect of phase-encoding direction on group analysis of resting-state functional magnetic resonance imaging
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DOI：
10.1111/pcn.12677
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发表时间：
2018-09-01
影响因子：
11.9
通讯作者：
Takahashi, Hidehiko
中科院分区：
文献类型：
--
作者：
Mori, Yasuo;Miyata, Jun;Takahashi, Hidehiko
目的回波平面成像是功能磁共振成像（fMRI）中常用的技术;然而，由于与扫描的相位编码方向相关的大的磁化率效应，它遭受图像失真和信号损失。尽管存在这种关系，但大多数神经影像学研究并未考虑相位编码方向的影响。在这里，我们的目的是澄清如何相位编码方向可以影响结果的fMRI连接性研究精神分裂症（SCZ）MethodsResting-state fMRI使用前向后（A-P）和后向前（P-A）的方向被用来检查25例SCZ和37名匹配的健康对照（HC）。我们使用独立成分分析进行了功能连接（FC）分析，并进行了三组比较：（i）A-P与P-A（所有参与者）;（ii）A-P和P-A数据集的SCZ与HC;和（iii）相位编码方向和参与者群体之间的相互作用。编码方向的区域比报告的信号丢失的区域更广泛。尽管SCZ组的FC在两个方向上均低于HC组，但A-P和P-A条件并未表现出相同的特定差异模式。此外，我们观察到的参与者群体之间的相互作用和相位编码方向在左颞顶交界处和左梭状回。因此，适当的选择和文件的相位编码方向将是重要的，在未来的静息态功能磁共振成像研究。
AimEcho-planar imaging is a common technique used in functional magnetic resonance imaging (fMRI); however, it suffers from image distortion and signal loss because of large susceptibility effects that are related to the phase-encoding direction of the scan. Despite this relation, the majority of neuroimaging studies has not considered the influence of phase-encoding direction. Here, we aimed to clarify how phase-encoding direction can affect the outcome of an fMRI connectivity study of schizophrenia (SCZ).MethodsResting-state fMRI using anterior to posterior (A-P) and posterior to anterior (P-A) directions was used to examine 25 patients with SCZ and 37 matched healthy controls (HC). We conducted a functional connectivity (FC) analysis using independent component analysis and performed three group comparisons: (i) A-P versus P-A (all participants); (ii) SCZ versus HC for the A-P and P-A datasets; and (iii) the interaction between phase-encoding direction and participant group.ResultsThe estimated FC differed between the two phase-encoding directions in areas that were more extensive than those where signal loss has been reported. Although FC in the SCZ group was lower than that in the HC group for both directions, the A-P and P-A conditions did not exhibit the same specific pattern of differences. Further, we observed an interaction between participant group and the phase-encoding direction in the left temporoparietal junction and left fusiform gyrus.ConclusionPhase-encoding direction can influence the results of FC studies. Thus, appropriate selection and documentation of phase-encoding direction will be important in future resting-state fMRI studies.