State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University Beijing, China.
Front Syst Neurosci. 2010 Jun 17;4:24. doi: 10.3389/fnsys.2010.00024. eCollection 2010.
In this study, we applied coherence to voxel-wise measurement of regional homogeneity of resting-state functional magnetic resonance imaging (RS-fMRI) signal. We compared the current method, regional homogeneity based on coherence (Cohe-ReHo), with previously proposed method, ReHo based on Kendall's coefficient of concordance (KCC-ReHo), in terms of correlation and paired t-test in a large sample of healthy participants. We found the two measurements differed mainly in some brain regions where physiological noise is dominant. We also compared the sensitivity of these methods in detecting difference between resting-state conditions [eyes open (EO) vs. eyes closed (EC)] and in detecting abnormal local synchronization between two groups [attention deficit hyperactivity disorder (ADHD) patients vs. normal controls]. Our results indicated that Cohe-ReHo is more sensitive than KCC-ReHo to the difference between two conditions (EO vs. EC) as well as that between ADHD and normal controls. These preliminary results suggest that Cohe-ReHo is superior to KCC-ReHo. A possible reason is that coherence is not susceptible to random noise induced by phase delay among the time courses to be measured. However, further investigation is still needed to elucidate the sensitivity and specificity of these methods.
在这项研究中,我们将相干性应用于静息态功能磁共振成像 (RS-fMRI) 信号的体素水平区域同质性测量。我们比较了当前的方法,基于相干性的区域同质性 (Cohe-ReHo),与先前提出的基于 Kendall 一致性系数 (KCC-ReHo) 的方法,在大量健康参与者的相关性和配对 t 检验中。我们发现这两种测量方法主要在一些生理噪声占主导地位的脑区存在差异。我们还比较了这些方法在检测静息状态条件(睁眼 (EO) 与闭眼 (EC))之间差异以及在检测两组之间异常局部同步方面的敏感性[注意缺陷多动障碍 (ADHD) 患者与正常对照组]。我们的结果表明,Cohe-ReHo 比 KCC-ReHo 更敏感,能够检测到两种条件(EO 与 EC)之间以及 ADHD 与正常对照组之间的差异。这些初步结果表明,Cohe-ReHo 优于 KCC-ReHo。一个可能的原因是相干性不受要测量的时间序列之间的相位延迟引起的随机噪声的影响。然而,仍需要进一步研究来阐明这些方法的敏感性和特异性。