Normalized functional MRI in human brain disorders

描述（由申请人提供）：本研究的长期目标是提高功能性磁共振成像（fMRI）在脑部疾病（特别是精神疾病）研究中的效用。对于这个项目，目标是集中在建立基线静脉氧合的MRI测量作为fMRI的生理标准化因子。首次将这种方法应用于精神分裂症将证明其临床可行性。具体目标是：1）优化和验证T2弛豫自旋标记下（TRUST）MRI。2)显示基线氧合对fMRI信号的影响，并证明TRUST MRI可用作受试者的标准化因子。3)采用TRUST MRI比较精神分裂症组和对照组对记忆任务的fMRI反应。功能磁共振成像在过去的15年中被广泛应用于无创评估大脑功能。也有很大的兴趣在应用功能磁共振成像精神疾病，如精神分裂症和阿尔茨海默氏病，与更好地了解这些疾病的认知后果的目标，重要的是，这些疾病的早期诊断的基础上的预期，功能改变之前的结构/行为的变化。然而，这些努力遇到了一些实际问题，许多研究发现，由于受试者群体之间的差异很大，结果是负面的。假设基线静脉血氧合的变化是受试者之间fMRI结果个体差异的主要原因，并且该参数的测量应允许校正此类差异。一种新的MRI技术，TRUST MRI，将被设计用于定量测量基线静脉氧合无创，并将进行校准和验证该技术。然后，TRUST MRI将用于使fMRI信号标准化，并提高检测两组受试者之间区域差异的灵敏度。一个“模型”的情况下，两个主题组已知有不同的神经活动将被用来评估该方法的实用性和功能磁共振成像灵敏度的改善。作为该技术的临床应用，将向精神分裂症患者提供记忆任务，并从fMRI反应中确定负责记忆缺陷的大脑区域，这可能会指导精神分裂症患者未来的治疗策略。

DESCRIPTION (provided by applicant): The long-term goal of this research is to improve the utility of functional magnetic resonance imaging (fMRI) in the studies of brain disorders, in particular psychiatric disorders. For this project, the goal is focused on the establishment of MRI measures of baseline venous oxygenation as a physiologic normalization factor for fMRI. The first application of this approach to Schizophrenia will demonstrate the clinical feasibility. The specific aims are: 1) Optimization and validation of T2-Relaxation-Under-Spin-Tagging (TRUST) MRI. 2) To show the effect of baseline oxygenation on fMRI signals and demonstrate that TRUST MRI can be used as a normalization factor across subjects. 3) To compare the fMRI responses to a memory task between a schizophrenia group and a control group using TRUST MRI. FMRI has been widely used over the past fifteen years to noninvasively evaluate the brain functions. There is also great interest in the application of fMRI to psychiatric disorders, such as Schizophrenia and Alzheimer's Disease, with the goal of better understanding the cognitive consequences of these diseases and, importantly, for early diagnosis of these diseases based on the expectation that functional alterations precede structural/behavioral changes. These efforts, however, have met with some practical problems and many studies have found results to be negative, due to large variations within the subject groups. It is hypothesized that variation in baseline venous blood oxygenation is the main reason for individual variation of fMRI results between subjects and that measurement of this parameter should allow correction for such differences. A novel MRI technique, TRUST MRI, will be devised to quantitatively measure the baseline venous oxygenation non-invasively, and calibration and validation of this technique will be performed. The TRUST MRI will then be used to normalize the fMRI signals and to improve the sensitivity in detecting regional differences between two groups of subjects. A "model" situation in which two subject groups are known to have different neural activities will be utilized to assess the utility of the approach and the improvement in fMRI sensitivity. As a clinical application of the technique, a memory task will be presented to the Schizophrenia patients and, from the fMRI responses, the brain regions that are responsible for the memory deficits will be determined, which may guide future treatment strategies for patients with Schizophrenia.