Global Signal Correction in Resting State fMRI

静息态 fMRI 中的全局信号校正

• 批准号: 8258622
• 负责人: THOMAS T LIU
• 金额: $ 23.22万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-27 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8258622
• 关键词: Adopted; Agreement; Brain; Brain region; Cardiac; Characteristics; Collection; Consensus; Data; Data Set; Dependence; Development; Disease; Electroencephalography; Functional Magnetic Resonance Imaging; Future; Goals; Health; Human; Knowledge; Magnetic Resonance Imaging; Maps; Measures; Methods; Metric; Modality; Performance; Physiological; Process; Rest; Series; Short-Term Memory; Signal Transduction; Source; Testing; Theoretical Studies; Time; United States National Institutes of Health; Variant; Work; base; clinical application; design; improved; interest; novel strategies; relating to nervous system; research study; respiratory; standard measure

DESCRIPTION (provided by applicant): Resting-state functional connectivity magnetic resonance imaging (fcMRI) has recently emerged as a leading method for non-invasively characterizing the functional connections of the human brain. In fcMRI studies, a standard measure of connectivity between two brain regions is the temporal correlation between their respective resting-state functional MRI (fMRI) time series. For the computation of correlations, many studies use a pre-processing step known as global signal regression (GSR), in which a global mean signal is subtracted from all voxel time courses. While GSR can greatly improve the consistency and reliability of functional connectivity maps, its use is controversial because it may also introduce spurious negative correlations. Currently, there is not a clear consensus regarding how to best handle global signal confounds, with many fcMRI studies still continuing to use GSR, while others have adopted alternate methods due to concerns about GSR. This lack of agreement makes it difficult to compare fcMRI studies, as differing approaches can yield significantly different connectivity measures. The goals of this project are to develop a better understanding of the global signal and to use that knowledge to develop new methods for global signal correction. The aims of the study are to (1) Develop and evaluate a new approach for global signal correction and (2) Determine whether global signal variations reflect changes in underlying neuroelectric coherence. PUBLIC HEALTH RELEVANCE: The proposed project will improve our ability to accurately measure functional connections in the brain using resting-state fMRI. Because the strength of functional connections may be an important indicator of the health of the brain, the proposed methods will benefit the study of a wide range of diseases.

描述（由申请人提供）：静止状态功能连通性磁共振成像（FCMRI）最近已成为非侵入性表征人脑功能连接的领先方法。在FCMRI研究中，两个大脑区域之间连通性的标准度量是它们各自的静止状态功能MRI（fMRI）时间序列之间的时间相关性。为了计算相关性，许多研究使用了称为全局信号回归（GSR）的预处理步骤，其中从所有Voxel时间课程中减去全局平均信号。尽管GSR可以大大提高功能连接图的一致性和可靠性，但其使用是有争议的，因为它也可能引入虚假的负相关。当前，关于如何最好地处理全球信号混杂的方式尚无明确的共识，许多FCMRI研究仍在继续使用GSR，而其他人则由于对GSR的担忧而采用了替代方法。缺乏一致性使得很难比较FCMRI研究，因为不同的方法可以产生明显不同的连接度量。该项目的目标是更好地理解全球信号，并利用该知识开发新的方法进行全球信号校正。该研究的目的是（1）开发和评估一种新的全局信号校正方法，（2）确定全局信号变化是否反映了潜在的神经电性相干性的变化。 公共卫生相关性：拟议的项目将提高我们使用静止状态fMRI准确测量大脑中功能连接的能力。由于功能连接的强度可能是大脑健康状况的重要指标，因此所提出的方法将使对广泛疾病的研究有益。