Friedman Lee, Glover Gary H
Department of Psychiatry, University of California-Irvine, Irvine, California, USA.
J Magn Reson Imaging. 2006 Jun;23(6):827-39. doi: 10.1002/jmri.20583.
Temporal stability during an fMRI acquisition is very important because the blood oxygen level-dependent (BOLD) effects of interest are only a few percent in magnitude. Also, studies involving the collection of groups of subjects over time require stable scanner performance over days, weeks, months, and even years. We describe a protocol designed by one of the authors that has been tested for several years within the context of a large, multicenter collaborative fMRI research project (FIRST-BIRN). A full description of the phantom, the quality assurance (QA) protocol, and the several calculations used to measure performance is provided. The results obtained with this protocol at multiple sites over time are presented. These data can be used as benchmarks for other centers involved in fMRI research. Some issues with the various protocol measures are highlighted and discussed, and possible protocol improvements are also suggested. Overall, we expect that other fMRI centers will find this approach to QA useful and this report may facilitate developing a similar QA protocol locally. Based on the findings reported herein, the authors are convinced that monitoring QA in this way will improve the quality of fMRI data.
功能磁共振成像（fMRI）采集过程中的时间稳定性非常重要，因为感兴趣的血氧水平依赖（BOLD）效应幅度仅为百分之几。此外，涉及随时间收集多组受试者的研究要求扫描仪在数天、数周、数月甚至数年的时间内保持稳定性能。我们描述了由一位作者设计的一种方案，该方案已在一个大型多中心协作fMRI研究项目（FIRST-BIRN）的背景下进行了数年测试。文中提供了体模、质量保证（QA）方案以及用于测量性能的几种计算方法的完整描述。展示了随着时间推移在多个站点使用该方案获得的结果。这些数据可作为其他参与fMRI研究的中心的基准。文中突出并讨论了各种方案测量方法存在的一些问题，并提出了可能的方案改进建议。总体而言，我们预计其他fMRI中心会发现这种质量保证方法很有用，并且本报告可能有助于在当地制定类似的质量保证方案。基于本文报告的研究结果，作者坚信以这种方式监测质量保证将提高fMRI数据的质量。
