Assessment of rodent brain activity using combined [15O]H2O-PET and BOLD-fMRI
Assessment of rodent brain activity using combined [15O]H2O-PET and BOLD-fMRI
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DOI：
10.1016/j.neuroimage.2013.11.044
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发表时间：
2014-04
期刊：
影响因子：
5.7
通讯作者：
H. Wehrl;P. Martirosian;F. Schick;G. Reischl;B. Pichler
中科院分区：
文献类型：
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作者：
H. Wehrl;P. Martirosian;F. Schick;G. Reischl;B. Pichler
小动物脑活动的研究是神经学研究的热点。在本研究中，我们提出了一种方案，利用短半衰期PET示踪剂[15O]H2O作为脑血流的标记物来监测大鼠须刺激后的脑激活。该技术能够在同一扫描过程中快速连续地研究基线和激活条件。此外，我们将PET成像结果与同一动物在同一麻醉过程中获得的额外BOLD-fMRI数据进行了比较。尽管与BOLD-fMRI结果相比，PET观察到的大脑活动期间的最大相对信号变化要高得多，但统计分析表明，PET中激活体素的数量比fMRI测量结果要低。此外，PET和fMRI在激活中心的形状和位置上都存在差异。与BOLD-fMRI相比，激活体素数量的差异可归因于PET图像的总体噪比较低，而空间位置的差异表明了一个更基本的过程，涉及PET和BOLD-fMRI反应的不同生理起源。本研究清楚地表明[15O]H2O-PET激活研究可以在小型实验动物中进行，并显示了使用[15O]H2O-PET和fMRI研究脑激活的互补性。
The study of brain activation in small animals is of high interest for neurological research. In this study, we proposed a protocol to monitor brain activation in rats following whisker stimulation using the short half-life PET tracer [15O]H2O as a marker for cerebral blood flow. This technique enables the study of baseline and activation conditions in fast succession within the same scanning session. Furthermore, we compared the results obtained from PET imaging with additional BOLD-fMRI data acquired in the same animals within the same anesthetic session in immediate succession. Although the maximum relative signal changes during brain activity observed with PET were substantially higher compared to the BOLD-fMRI results, statistical analyses showed that the number of activated voxels in PET was lower compared to the fMRI measurements. Furthermore, there was a difference in the activation centers in both the shape and location between PET and fMRI. The discrepancy in the number of activated voxels could be attributed to a lower overall contrast-to-noise ratio of the PET images compared to BOLD-fMRI, whereas the difference in the spatial location indicates a more fundamental process, involving the different physiological origins of the PET and BOLD-fMRI response. This study clearly demonstrates that [15O]H2O-PET activation studies may be performed in small laboratory animals, and shows the complementary nature of studying brain activation using [15O]H2O-PET and fMRI.