MRI MEASUREMENT OF RELATIVE CMR02-- VALIDATION USING PET

这项名为“相对CMRO2的磁共振成像测量：使用正电子发射计算机断层扫描(PET)进行验证”的资助提案是对R01奖项的申请。该项目的目标是1)在动物模型和人类志愿者中建立和验证不同生理条件下相对脑局部氧利用代谢率(RCMRO2)的定量成像方法；2)在神经调节局灶性脑激活的背景下，验证CMRO2的变化与血流动力学之间的关系。基本假设是，MR测量多个血流动力学观测数据-BOLD信号、CBF和CBV-将能够在啮齿动物和人类中进行与正电子发射断层扫描相一致的相对CMRO2的区域和时间评估。这些研究将进一步检验脑生理学的一个科学假说：CMRO2和CBF的变化总体上符合氧气从血液到脑组织的扩散限制模型，并得到初步数据的证实。在这个框架内，我们将测试关于MRI信号与潜在物理和生理之间关系的基本假设，并为相对CMRO2和CBF的MR1测量提供确证数据。这些拟议研究的成功完成将为脑功能生理学的评估建立一个新的工具，并为这些技术在脑病理学中的应用铺平序幕。

This grant proposal, "MRI Measurement of Relative CMRO2: Validation using PET", is an application for an R01 award. The goal of the proposed project is to 1) develop and validate MR methods for quantitative imaging of the relative regional cerebral metabolic rate of oxygen utilization (rCMRO2) under different physiological conditions in animal models and in human volunteers, and 2) validate the relationship between changes in CMRO2 and hemodynamics in the setting of neuronally-modulated focal brain activation. The fundamental hypothesis is that MR measurements of multiple hemodynamic observables - BOLD signal, CBF, and CBV - will enable regional and temporal assessment of relative CMRO2 in agreement with positron emission tomography in rodents and humans. These studies will further test a scientific hypothesis of cerebral physiology: that changes in CMRO2 and CBF exhibit a coupling relationship in general accordance with diffusion-limited models of oxygen delivery from the blood to brain tissue, and as demonstrated by preliminary data. Within this framework we will test the basic assumptions about the relationship between MRI signals and the underlying physics and physiology and provide corroborative data for MR1 measurements of relative CMRO2 and CBF. Successful completion of the proposed studies will establish, a new tool for assessment of cerebral functional physiology and preface the application of these techniques to cerebral pathology.