Test-retest and between-site reliability in a multicenter fMRI study
Test-retest and between-site reliability in a multicenter fMRI study
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DOI：
10.1002/hbm.20440
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发表时间：
2008-08-01
影响因子：
4.8
通讯作者：
Potkin, Steven G.
中科院分区：
文献类型：
--
作者：
Friedman, Lee;Stern, Hal;Potkin, Steven G.
在本报告中，在多中心fMRI可靠性研究（FBIRN第1期，www.nbirn.net）的背景下，对fMRI评估的测试-重测试和站点间可靠性进行了估计。五名受试者分别在两种情况下使用10台核磁共振扫描仪进行扫描。fMRI任务是一个简单的块设计感觉运动任务。利用FMRISTAT进行FIR-cleconvolution分析，得到了刺激区块的脉冲响应函数。使用了从先前分析中创建的涵盖视觉，听觉和运动皮质的六个功能衍生的rol。比较了两个因变量：信号变化百分比和噪比。通过方差成分分析得出的类内相关系数来评估可靠性。测试-重测信度很高，但最初，站点之间的信度很低，表明站点和站点-受试者方差的贡献很大。然而，研究人员发现了许多可以显著提高站点间可靠性的因素，包括增加rol的大小，调整平滑度差异，以及包含额外的运行。通过采用多个步骤，3T扫描仪的站点间可靠性提高了123%。每次删除一个站点并评估可靠性可能是评估结果对特定站点的敏感性的有用方法。这些发现应该为未来多中心研究的最佳实践提供指导。
In the present report, estimates of test-retest and between-site reliability of fMRI assessments were produced in the context of a multicenter fMRI reliability study (FBIRN Phase 1, www.nbirn.net). Five subjects were scanned on 10 MRI scanners on two occasions. The fMRI task was a simple block design sensorimotor task. The impulse response functions to the stimulation block were derived using an FIR-cleconvolution analysis with FMRISTAT. Six functionally-derived ROls covering the visual, auditory and motor cortices, created from a prior analysis, were used. Two dependent variables were compared: percent signal change and contrast-to-noise-ratio. Reliability was assessed with intraclass correlation coefficients derived from a variance components analysis. Test-retest reliability was high, but initially, between-site reliability was low, indicating a strong contribution from site and site-by-subject variance. However, a number of factors that can markedly improve between-site reliability were uncovered, including increasing the size of the ROls, adjusting for smoothness differences, and inclusion of additional runs. By employing multiple steps, between-site reliability for 3T scanners was increased by 123%. Dropping one site at a time and assessing reliability can be a useful method of assessing the sensitivity of the results to particular sites. These findings should provide guidance to others on the best practices for future multicenter studies.