Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland 20892-2035, USA.
Neuroimage. 2011 Feb 1;54(3):1903-9. doi: 10.1016/j.neuroimage.2010.10.064. Epub 2010 Oct 26.
(11)C-rolipram provides a measure of the density of phosphodiesterase 4 (PDE4) in brain, an enzyme that metabolizes cAMP. The aims of this study were to perform kinetic modeling of (11)C-rolipram in healthy humans using an arterial input function and to replace this arterial input in humans with an image-derived input function.
Twelve humans had two injections of (11)C-rolipram. An image-derived input function was obtained from the carotid arteries and four blood samples. The samples were used for partial volume correction and for estimating the parent concentration using HPLC analysis.
An unconstrained two-compartment model and Logan analysis measured distribution volume V(T), with good identifiability but with moderately high retest variability (15%). Similar results were obtained using the image input (ratio image/arterial V(T)=1.00±0.06).
Binding of (11)C-rolipram to PDE4 can be quantified in human brain using kinetic modeling and an arterial input function. Image input function from carotid arteries provides an equally accurate and reproducible method to quantify PDE4.
(11)C-罗利普兰为大脑中的磷酸二酯酶 4（PDE4）密度提供了一种衡量标准，该酶代谢 cAMP。本研究的目的是使用动脉输入函数对健康人类的(11)C-罗利普兰进行动力学建模，并用人脑图像衍生输入函数替代这种动脉输入。
12 名健康人接受了两次(11)C-罗利普兰注射。从颈动脉获得图像衍生输入函数和 4 个血样。使用这些样本进行部分容积校正，并使用 HPLC 分析来估计母体浓度。
无约束的两室模型和 Logan 分析测量了分布容积 V(T)，具有良好的可识别性，但复测变异性中等偏高（15%）。使用图像输入（图像/动脉 V(T)比=1.00±0.06）也得到了相似的结果。
使用动力学建模和动脉输入函数可以在人类大脑中定量测定(11)C-罗利普兰与 PDE4 的结合。颈动脉的图像输入函数提供了一种同样准确和可重复的定量 PDE4 的方法。
