ABSOLUTE CEREBRAL BLOOD FLOW QUANTIFICATION WITH ASL DURING HYPEROXIA

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 一些研究已经使用动脉自旋标记(ASL)方法来研究高氧下局部脑血流量的变化。虽然众所周知，吸入氧气会显著降低动脉血的T1(T1a)，而且T1a对使用ASL测量CBF有很大影响，但这些研究中只有一小部分将这些T1a的变化纳入了CBF计算。在这些研究中，一些研究人员利用高氧期间T1a的先前研究结果来估计T1a的平均预期变化。其他人被要求模拟T1a的预期变化，因为这项研究是在3Tesla(T)进行的，在那里没有关于高氧期间T1a的文献数据。由于几个原因，这些方法可能是有问题的。在这个项目中，我们的目标是使用脉冲ASL方法在体内同时测量常氧和高氧状态下的CBF和T1a。这将允许在每个受试者的基础上对由于T1a减少而导致的CBF数据进行准确的校正，从而可以量化用ASL测量的CBF减少的程度是由于T1a。在这种情况下，大鼠被用作动物模型，因为自旋从传输线圈外部流入的并发症。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Several studies have used arterial spin labeling (ASL) approaches to investigate the regional CBF changes with hyperoxia. Although it is well-known that inhaled oxygen creates a significant reduction in the T1 of arterial blood (T1a), and that T1a has a substantial effect on CBF measurements using ASL, only a small number of these studies have incorporated these T1a changes in their CBF calculations. For these studies, some investigators used the results of prior studies of T1a during hyperoxia to estimate an average expected change in T1a. Others were required to model the expected change in T1a because the study was performed at 3 Tesla (T), where there is no literature data available on T1a during hyperoxia. These approaches may be problematic for several reasons. In this project, our aim was to simultaneously measure CBF and T1a in vivo during normoxia and hyperoxia using pulsed ASL approaches. This will allow for an accurate correction of CBF data due to reduction in T1a on a per subject basis, allowing for the quantification of the degree to which the reduction in CBF measured with ASL are due to T1a. Rats are used as animal model in this case because of the complication of spins flowing in from outside of the transmit coil.