Validating Resting State fMRI Derived Brain Connectivity

描述(申请人提供)：这项名为“验证静息状态fMRI衍生的脑连通性”的项目代表了一项大规模的努力，旨在严格建立由静息状态fMRI(FcMRI)衍生的大脑连通性测量的可靠性。这种研究大脑各区域之间连通性的空间模式的方法最近经历了一个密集的增长期。最近的出版物表明，该方法可能能够洞察大脑区域之间相互作用的大规模结构，这些结构支持人类健康中大脑的综合功能。也有越来越多的文献表明，偏离正常观察到的连接模式可能是许多精神健康疾病的根本原因，包括精神分裂症、抑郁症和自闭症。在应用该方法时，在计算连通性的统计测量之前，必须对数据应用大量的处理步骤。目前缺乏关于不同的前处理方法对使用fcMRI获得的结果的可靠性的影响的知识。所需的一种处理包括去除由心脏和呼吸引起的大脑脉动引起的信号变化。目前，通常使用简单的数字滤波方法。理论上的考虑表明，这种类型的处理可能不会给出最佳结果。这项研究将调查通过使用更复杂的方法可能实现的改进，这些方法包括利用在MRI扫描时从受试者测量的心脏和呼吸周期的记录。影响结果准确性和可靠性的另一个因素涉及为了在受试者之间进行比较而必须进行的处理。为了可以在不同受试者的相应大脑区域之间进行比较，必须使大脑扫描保持一致。在神经科学界，众所周知，用于实现这一点的不同数学工具是不完美的，不同的方法会带来不同的误差。这项研究将调查应用不同方法来完成这一比对在可靠性上的差异。为了使这项研究的结果足够普遍，以作为研究人员的指南，我们将从大量健康个体中获取fcMRI数据，并使用一种称为Bootstrap设计的研究设计。将从大约100名志愿者每人那里获得多个MRI数据集。来自所有受试者的数据将用研究中考虑的每一种不同的处理方法进行处理。该方法遵循选择受试者子集和计算fcMRI测量的程序。接下来，根据前述结果计算受试者内和受试者间的信度。这一基本程序被重复大量次，建立了一组可用于计算可靠统计数据的大量测量数据。这项研究的结果将有助于功能磁共振领域的研究人员进行更知情的研究设计，并帮助解释结果的有效性。这项研究代表了fcMRI作为表征正常和病理脑功能的生物标记物的必要的下一步。这项研究旨在验证一种名为静息状态功能磁共振成像的新兴方法在了解人类和动物大脑连接方面的结果。它将有助于指导从业人员利用这一方法实现最佳结果的技术要求。这项拟议的研究对基础神经科学和临床神经科学都有贡献，并将为未来研究正常人群的大脑连接和不同患者群体的连接中断提供基础。

DESCRIPTION (provided by applicant): This project titled 'Validating resting state fMRI derived brain connectivity' represents a large scale effort to establish rigorously the reliability of brain connectivity measures derived from resting state fMRI (fcMRI). This method of studying the spatial pattern of connectivity between regions of the brain has recently seen an intensive period of growth. Recent publications indicate the method may be able to give insight into the large scale structure of interactions between brain regions that support the integrated functioning of the brain in human health. There is also a growing body of literature that indicates deviations from the normally observed pattern of connectivity may be a fundamental causative factor in many mental health disorders including schizophrenia, depression, and autism. In applying this method there are a large number of processing steps that must be applied to the data before the statistical measures of connectivity are calculated. There is currently a lack of knowledge as to the effects of different methods of preprocessing on the reliability of the results obtained using fcMRI. One type of processing required involves the removal of variations in the signal resulting from cardiac and respiratory induced pulsations in the brain. Currently simple digital filtering methods are usually used. Theoretical considerations indicate this type of processing may not give optimal results. This study will investigate the improvements that may be achieved by using more complex methods that involve utilizing recordings of the cardiac and respiratory cycle measured from the subject at the time of MRI scanning. Another factor that influences the accuracy and reliability of the results concerns processing that must be performed in order that comparisons between subjects may be made. In order that comparisons may be made between corresponding brain regions of different subjects the brain scans must be brought into alignment. It is well known in the neuroscience community that the different mathematical tools used to accomplish this are imperfect and that different methods introduce different errors. This study will investigate the differences in reliability that result from the application of the different methods to accomplish this alignment. In order that the results of the study will be sufficiently general to serve as a guide for investigators we will acquire fcMRI data from a large number of healthy individuals and use a study design known as a bootstrap design. Multiple MRI data sets will be acquired from each of approximately 100 volunteers. The data from all subjects will be processed with each of the different processing methods considered in the study. The methodology follows a procedure of choosing subsets of the subjects and calculating fcMRI measures. Next measures of the intra subject and intersubject reliability are calculated from the proceeding results. This basic procedure is repeated a large number of times building a large set of measurements from which reliable statistics may be calculated. The results derived from this study will serve to enable researchers in the field of fcMRI to conduct more informed study design and aid in the interpretation of the validity of results. This study represents an essential next step in the validation of fcMRI as a biomarker for the characterization of normal and pathological brain function. The research is intended to validate the results of an emerging method known as resting state fmri in understanding human and animal brain connectivity. It would serve to guide practitioners of the technical requirements for achieving optimal results utilizing this method. This proposed research contributes to both basic neuroscience and clinical neuroscience and will provide the foundation for future studies characterizing brain connectivity in normals and disruptions of connectivity in various patient populations.