Yen C K, Pollycove M, Crass R, Lin T H, Baldwin R, Lamb J
J Nucl Med. 1986 Aug;27(8):1321-6.
Portasystemic shunting was quantified in dogs with [123I]iodoamphetamine (IMP) administered transrectally into the colon and monitored externally with a gamma camera. IMP was absorbed rapidly and unchanged from the colon. After direct injection into the portal vein, IMP was almost completely extracted by the liver on the first pass, and the washout half-life was approximately 60 min. Based on these kinetic data, computer simulation of this biologic system was carried out. Errors associated with simplified models are calculated. The simplest model with insignificant error, which assumed that the tracer behaved like microspheres, was used to quantitate portasystemic shunt fraction in animals with surgically created shunts. Results were compared with the standard of 99mTc-labeled macroaggregated albumin infused into a branch of inferior mesenteric vein. For shunt fractions ranging from 0 to 100%, an excellent correlation was seen, indicating that this approach is potentially a simple, noninvasive method of portasystemic shunt fraction quantification.
经直肠将[123I]碘安非他明（IMP）注入犬结肠，并通过γ相机进行外部监测，以此对门体分流进行定量分析。IMP在结肠中迅速被吸收且未发生变化。直接注入门静脉后，IMP在首次通过肝脏时几乎被完全摄取，洗脱半衰期约为60分钟。基于这些动力学数据，对该生物系统进行了计算机模拟。计算了与简化模型相关的误差。使用误差不显著的最简单模型（该模型假定示踪剂的行为类似于微球）对有手术造瘘的动物的门体分流分数进行定量。将结果与注入肠系膜下静脉分支的99mTc标记的大聚合白蛋白的标准进行比较。对于分流分数范围为0至100%的情况，观察到了极佳的相关性，这表明该方法可能是一种简单的、非侵入性的门体分流分数定量方法。
