Gallezot Jean-Dominique, Zheng Ming-Qiang, Lim Keunpoong, Lin Shu-fei, Labaree David, Matuskey David, Huang Yiyun, Ding Yu-Shin, Carson Richard E, Malison Robert T
PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut.
J Nucl Med. 2014 Jun;55(6):960-6. doi: 10.2967/jnumed.113.132928. Epub 2014 Apr 14.
(11)C-(+)-4-propyl-9-hydroxynaphthoxazine ((11)C-(+)-PHNO) is an agonist radioligand for imaging dopamine D2 and D3 receptors in the human brain with PET. In this study we evaluated the reproducibility of (11)C-(+)-PHNO binding parameters using a within-day design and assessed parametric imaging methods.
Repeated studies were performed in 8 subjects, with simultaneous measurement of the arterial input function and plasma free fraction. Two (11)C-(+)-PHNO scans for the same subject were separated by 5.4 ± 0.7 h. After compartment models were evaluated, (11)C-(+)-PHNO volumes of distribution (V(T)) and binding potentials relative to the concentration of tracer in plasma (BP(P)), nondisplaceable tracer in tissue (BP(ND)), and free tracer in tissue (BP(F)) were quantified using the multilinear analysis MA1 method, with the cerebellum as the reference region. Parametric images of BP(ND) were also computed using the simplified reference tissue model (SRTM) and SRTM2.
The test-retest variability of (11)C-(+)-PHNO BP(ND) was 9% in D2-rich regions (caudate and putamen). Among D3-rich regions, variability was low in the pallidum (6%) but higher in substantia nigra (19%), thalamus (14%), and hypothalamus (21%). No significant mass carry-over effect was observed in D3-rich regions, although a trend in BP(ND) was present in the substantia nigra (-14% ± 15%). Because of the relatively fast kinetics, low-noise BP(ND) parametric images were obtained with both SRTM and SRTM2 without spatial smoothing.
(11)C-(+)-PHNO can be used to compute low-noise parametric images in both D2- and D3-rich regions in humans.
（11）C-（+）-4-丙基-9-羟基萘恶嗪（（11）C-（+）-PHNO）是一种激动剂放射性配体，用于正电子发射断层扫描（PET）成像人脑中的多巴胺D2和D3受体。在本研究中，我们使用日内设计评估了（11）C-（+）-PHNO结合参数的可重复性，并评估了参数成像方法。
对8名受试者进行重复研究，同时测量动脉输入函数和血浆游离分数。同一受试者的两次（11）C-（+）-PHNO扫描间隔5.4±0.7小时。在评估房室模型后，以小脑为参考区域，使用多线性分析MA1方法对（11）C-（+）-PHNO分布容积（V（T））以及相对于血浆中示踪剂浓度（BP（P））、组织中不可置换示踪剂（BP（ND））和组织中游离示踪剂（BP（F））的结合电位进行定量。还使用简化参考组织模型（SRTM）和SRTM2计算BP（ND）的参数图像。
在富含D2的区域（尾状核和壳核），（11）C-（+）-PHNO BP（ND）的重测变异性为9%。在富含D3的区域中，苍白球的变异性较低（6%），但黑质（19%）、丘脑（14%）和下丘脑（21%）的变异性较高。在富含D3的区域未观察到明显的质量残留效应，尽管黑质中BP（ND）存在一种趋势（-14%±15%）。由于动力学相对较快，使用SRTM和SRTM2均可获得低噪声的BP（ND）参数图像，无需空间平滑处理。
（11）C-（+）-PHNO可用于计算人类富含D2和D3区域的低噪声参数图像。
