Stroman Patrick W
Centre for Neuroscience Studies, Queen's University, 2nd floor, Botterell Hall, 18 Stuart Street, Kingston, ON, Canada K7L 3N6; Department of Physics, Queen's University, Kingston, ON, Canada, K7L 3N6.
Crit Rev Biomed Eng. 2016;44(4):227-241. doi: 10.1615/CritRevBiomedEng.2017020438.
Structural equation modeling (SEM) provides a means of investigating relationships between blood oxygenation level-dependent (BOLD) signal changes in functional MRI data across neuroanatomical regions. The objectives of this study were to demonstrate adapted SEM methods for the brainstem and spinal cord, validate statistical methods and appropriate statistical thresholds, and test the methods with existing data. SEM methods were applied using an anatomical model of regions of the thalamus, brainstem, and spinal cord that are involved with pain processing. Statistical distributions (Z-scores), significance thresholds, and corrections for multiple comparisons were determined from repeated simulations using "null" data sets. SEM analyses were then applied to data from prior studies involving noxious stimulation in healthy participants. Z-score distributions were observed to vary with the number of source regions modeled, the number of time points (volumes) included in the analysis, and the time span (epoch) used for dynamic analyses. Appropriate choices of statistical thresholds and corrections for multiple comparisons were demonstrated. The results reveal consistent network features across/within studies, as well as dependences on study conditions. They show the effectiveness of a SEM method for functional MRI data from the brainstem and spinal cord.
结构方程模型（SEM）提供了一种研究功能磁共振成像（fMRI）数据中跨神经解剖区域的血氧水平依赖（BOLD）信号变化之间关系的方法。本研究的目的是展示适用于脑干和脊髓的SEM方法，验证统计方法和合适的统计阈值，并使用现有数据测试这些方法。使用涉及疼痛处理的丘脑、脑干和脊髓区域的解剖模型应用SEM方法。通过使用“空”数据集的重复模拟确定统计分布（Z分数）、显著性阈值和多重比较校正。然后将SEM分析应用于先前涉及健康参与者有害刺激的研究数据。观察到Z分数分布随建模的源区域数量、分析中包含的时间点（体积）数量以及用于动态分析的时间跨度（时期）而变化。证明了统计阈值和多重比较校正的适当选择。结果揭示了不同研究之间/内部一致的网络特征以及对研究条件的依赖性。它们显示了一种SEM方法对来自脑干和脊髓的功能磁共振成像数据的有效性。
