Interpreting oxygenation-based neuroimaging signals: the importance and the challenge of understanding brain oxygen metabolism.
Interpreting oxygenation-based neuroimaging signals: the importance and the challenge of understanding brain oxygen metabolism.
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DOI：
10.3389/fnene.2010.00008
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发表时间：
2010
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影响因子：
--
通讯作者：
Buxton RB
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文献类型：
--
作者：
Buxton RB
功能性磁共振成像被广泛用于基于与神经活动变化相关的血氧水平依赖（BOLD）信号变化来映射脑激活模式。然而，由于氧合变化取决于脑血流量（CBF）和脑氧代谢率（CMRO2）的相对变化，因此BOLD信号以及与血液或组织氧合相关的其他功能性神经成像信号的定量解释从根本上受到限制，直到我们更好地了解脑氧代谢及其与血流的关系。然而，氧合信号复杂性的积极方面是，当与动态CBF测量相结合时，它们可能提供目前可用于研究CMRO2动态的最佳工具。本综述重点介绍了解释基于氧合的信号的问题，测量CMRO2的挑战，以及将基于氧合的CMRO2估计建立在坚实基础上所需的内容。发展一个坚实的理论框架的重要性被强调，无论是作为一个必要的工具，用于分析基于氧合的多模态测量，也可能作为一种方式，以更好地了解生理现象本身。现有的数据，整合在一个简单的理论框架内的O2运输，建议的假设，一个重要的功能作用的不匹配的CBF和CMRO2的变化与神经激活是为了防止下降的组织pO2。未来的方向，更好地了解脑氧代谢进行了讨论。
Functional magnetic resonance imaging is widely used to map patterns of brain activation based on blood oxygenation level dependent (BOLD) signal changes associated with changes in neural activity. However, because oxygenation changes depend on the relative changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2), a quantitative interpretation of BOLD signals, and also other functional neuroimaging signals related to blood or tissue oxygenation, is fundamentally limited until we better understand brain oxygen metabolism and how it is related to blood flow. However, the positive side of the complexity of oxygenation signals is that when combined with dynamic CBF measurements they potentially provide the best tool currently available for investigating the dynamics of CMRO2. This review focuses on the problem of interpreting oxygenation-based signals, the challenges involved in measuring CMRO2 in general, and what is needed to put oxygenation-based estimates of CMRO2 on a firm foundation. The importance of developing a solid theoretical framework is emphasized, both as an essential tool for analyzing oxygenation-based multimodal measurements, and also potentially as a way to better understand the physiological phenomena themselves. The existing data, integrated within a simple theoretical framework of O2 transport, suggests the hypothesis that an important functional role of the mismatch of CBF and CMRO2 changes with neural activation is to prevent a fall of tissue pO2. Future directions for better understanding brain oxygen metabolism are discussed.