Vera D R, Scheibe P O, Krohn K A, Trudeau W L, Stadalnik R C
Department of Radiology, University of California, Davis, Medical Center, Sacramento 95817.
IEEE Trans Biomed Eng. 1992 Apr;39(4):356-67. doi: 10.1109/10.126608.
A four-state nonlinear model describing a radiopharmacokinetic system for a hepatic receptor-binding radiopharmaceutical, [99mTc]-galactosyl-neoglycoalbumin (TcNGA), was tested for goodness-of-fit and local identifiability using scanning data from nine healthy subjects and seven patients with severe liver disease. Based on standard deviations of liver and heart imaging data at equilibria as a measure of observational error, the reduced chi-square ranged from 0.5 to 2.6. Values above 1.2 occurred when the subject moved during the 30 min study. Relative standard errors for each parameter were: TcNGA-receptor forward binding rate constant kb, 13-54%; extra-hepatic plasma volume Ve, 0.8-15.0%; hepatic plasma volume Vh, 0.2-6.5%; hepatic plasma flow F, 54----greater than 1000%; and receptor concentration [R]o, 0.3-13%. The highest standard errors occurred when the amount of TcNGA injected exceeded the total amount of receptor. Therefore, when TcNGA functional imaging was performed without excess patient motion and receptor saturation, the kinetic model provided data fits of low systematic error and yielded high precision estimates of receptor concentration and forward binding rate constant. In summary, optimal performance of the kinetic model occurred when the amount of injected TcNGA resulted in the nonlinear operation of the pharmacokinetic system.
一个描述肝脏受体结合放射性药物[99mTc] - 半乳糖基新糖白蛋白（TcNGA）放射性药代动力学系统的四态非线性模型，使用来自9名健康受试者和7名严重肝病患者的扫描数据进行了拟合优度和局部可识别性测试。以平衡时肝脏和心脏成像数据的标准差作为观测误差的度量，约化卡方值范围为0.5至2.6。当受试者在30分钟研究期间移动时，会出现高于1.2的值。每个参数的相对标准误差为：TcNGA - 受体正向结合速率常数kb，13 - 54%；肝外血浆体积Ve，0.8 - 15.0%；肝血浆体积Vh，0.2 - 6.5%；肝血浆流量F，54%至大于1000%；以及受体浓度[R]o，0.3 - 13%。当注入的TcNGA量超过受体总量时，标准误差最高。因此，当在没有过多患者移动和受体饱和的情况下进行TcNGA功能成像时，动力学模型提供了低系统误差的数据拟合，并对受体浓度和正向结合速率常数产生了高精度估计。总之，当注入的TcNGA量导致药代动力学系统非线性运行时，动力学模型表现最佳。
