Quantification of regional cerebral blood flow in rats using an arteriovenous shunt and micro-PET
Quantification of regional cerebral blood flow in rats using an arteriovenous shunt and micro-PET
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DOI：
10.1016/j.nucmedbio.2011.11.004
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发表时间：
2012-07-01
影响因子：
3.1
通讯作者：
Iida, Hidehiro
中科院分区：
文献类型：
--
作者：
Ose, Takayuki;Watabe, Hiroshi;Iida, Hidehiro
简介：测量啮齿动物的局部脑血流量（rCBF）可以提供脑循环病理生理学的知识，但通常需要在正电子发射断层扫描（PET）过程中采集血液样本进行分析。因此，我们测试了在大鼠中使用动静脉 (AV) 分流器进行微创血液分析的可行性。方法：六只麻醉大鼠接受 [O-15]H2O 和 [O-15]CO PET 扫描，其股动脉和静脉通过 AV 分流器连接，其中的活动用原硅酸锗闪烁探测器测量。 [O-15]H2O 以更快或更慢的注射速率静脉注射，同时将动物放置在其头部或心脏位于龙门中心的位置。将 AV 分流的时间活动曲线 (TAG) 与 PET 图像中心室的时间活动曲线 (TAG) 进行比较。使用色散校正的 AV 分流 TAG 作为输入，通过非线性最小二乘法计算 rCBF 值。结果：与图像衍生 TAG 相比，AV 分流 TAG 具有更高的信噪比，但也存在延迟和色散。 AV 分流 TAG 和基于图像的 TAG 之间的延迟时间范围为 11 至 21 s，而作为指数函数色散模型的时间常数，色散估计类似于 5 s，并且两者都得到了适当的校正。在 [O-15]CO PET 的稳态条件下，AV 分流 TAG 的血液活性浓度在高度上也与针对部分体积进行校正的基于图像的 TAG 相当。 [O-15]H2O 测量的全脑 CBF 值为 0.37+/-0.04 (平均值+/-S.D.) ml/g/min，分配系数为 0.73+/-0.04 ml/g，每次扫描期间 CBF 变化与二氧化碳分压呈线性关系。结论：AV 分流技术可以对 [O-15]H2O 中的 rCBF 进行侵入性较小、定量且可重复的测量对大鼠进行 PET 研究优于直接采血和放射测定。 (C) 2012 Elsevier Inc. 保留所有权利。
Introduction: Measurement of regional cerebral blood flow (rCBF) in rodents can provide knowledge of pathophysiology of the cerebral circulation, but generally requires blood sampling for analysis during positron emission tomography (PET). We therefore tested the feasibility of using an arteriovenous (AV) shunt in rats for less invasive blood analysis.Methods: Six anesthetized rats received [O-15]H2O and [O-15]CO PET scans with their femoral artery and vein connected by an AV shunt, the activity within which was measured with a germanium ortho-oxysilicate scintillation detector. The [O-15]H2O was intravenously injected either at a faster or slower injection rate, while animals were placed either with their head or heart centered in the gantry. The time activity curve (TAG) from the AV shunt was compared with that from the cardiac ventricle in PET image. The rCBF values were calculated by a nonlinear least-square method using the dispersion-corrected AV-shunt TAG as an input.Results: The AV-shunt TAG had higher signal-to-noise ratio, but also had delay and dispersion compared with the image-derived TAG. The delay time between the AV-shunt TAG and image-based TAG ranged from 11 to 21 s, while the dispersion was estimated to be similar to 5 s as a time constant of the dispersion model of exponential function, and both were properly corrected. In a steady-state condition of [O-15]CO PET, the blood activity concentration by AV-shunt TAG was also comparable in height with the image-based TAG corrected for partial volume. Whole-brain CBF values measured by [O-15]H2O were 0.37+/-0.04 (mean+/-S.D.) ml/g/min, partition coefficient was 0.73+/-0.04 ml/g, and the CBF varied in a linear relationship with partial pressure of carbon dioxide during each scan.Conclusions: The AV-shunt technique allows less invasive, quantitative and reproducible measurement of rCBF in [O-15]H2O PET studies in rats than direct blood sampling and radioassay. (C) 2012 Elsevier Inc. All rights reserved.