Caffeine reduces the activation extent and contrast-to-noise ratio of the functional cerebral blood flow response but not the BOLD response
Caffeine reduces the activation extent and contrast-to-noise ratio of the functional cerebral blood flow response but not the BOLD response
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DOI：
10.1016/j.neuroimage.2008.04.177
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发表时间：
2008-08-01
期刊：
影响因子：
5.7
通讯作者：
Liu, Thomas T.
中科院分区：
文献类型：
--
作者：
Liau, Joy;Perthen, Joanna E.;Liu, Thomas T.
功能激活的空间范围的测量对于许多功能性磁共振成像（fMRI）应用是重要的，例如手术前规划和随着疾病进展和药物治疗的脑激活变化的纵向跟踪。从这些应用程序中的数据的解释可以是复杂的测量的功能磁共振成像信号的受试者之间或会话之间的变化。先前的研究表明，基线脑血流量（CBF）的调制可以直接改变功能CBF和血氧水平依赖（BOLD）的反应，这表明基于这些信号的功能激活图的空间范围也可能取决于基线CBF。在这项研究中，我们使用咖啡因剂量（200 mg）降低基线CBF，发现CBF激活程度和对比噪声比（CNR）均显著降低（p < 0.05），但BOLD激活程度和CNR无显著变化。与此相反，咖啡因显着改变的BOLD响应的时间动态，但没有CBF响应。CBF激活程度和CNR的降低与咖啡因诱导的绝对CBF变化的显著降低一致，同时残留噪声没有显著变化。基线CBF的测量值也是CBF激活图面积和CNR中受试者间变异性的重要部分。因此，在解释使用功能性CBF激活图的研究时，应仔细考虑可调节基线CBF的因素，如年龄、药物和疾病。(c)2008年爱思唯尔公司All rights reserved.
Measures of the spatial extent of functional activation are important for a number of functional magnetic resonance imaging (fMRI) applications, such as pre-surgical planning and longitudinal tracking of changes in brain activation with disease progression and drug treatment. The interpretation of the data from these applications can be complicated by inter-subject or inter-session variability in the measured fMRI signals. Prior studies have shown that modulation of baseline cerebral blood flow (CBF) can directly alter the functional CBF and blood oxygenation level dependent (BOLD) responses, suggesting that the spatial extents of functional activation maps based on these signals may also depend on baseline CBF. In this study, we used a caffeine dose (200 mg) to decrease baseline CBF and found significant (p < 0.05) reductions in both the CBF activation extent and contrast-to-noise ratio (CNR) but no significant changes in the BOLD activation extent and CNR. In contrast, caffeine significantly changed the temporal dynamics of the BOLD response but not the CBF response. The decreases in the CBF activation extent and CNR were consistent with a significant caffeine-induced decrease in the absolute CBF change accompanied by no significant change in the residual noise. Measures of baseline CBF also accounted for a significant portion of the inter-subject variability in the CBF activation map area and CNR. Factors that can modulate baseline CBF, such as age, medication, and disease, should therefore be carefully considered in the interpretation of studies that use functional CBF activation maps. (c) 2008 Elsevier Inc. All rights reserved.