Comparison of Tc-99m labeled liver and liver paté as markers for solid-phase gastric emptying.

A radionuclide marker for studies of solid-phase gastric emptying should have a high labeling efficiency and remain relatively stable during gastric emptying. The availability of materials and the ease of preparation are also considerations in selecting radionuclide markers. We have compared the stability of intracellularly labeled chicken liver, surface-labeled chicken liver, and labeled puréed meat (liver paté) incubated with hydrochloric acid solution or gastric juice. Intracellularly labeled chicken liver and labeled liver paté were also compared in gastric emptying studies in humans. Our in vitro results demonstrated labeling efficiencies greater than 92% for both intracellularly labeled liver and labeled liver paté. The paté labeled with Tc-99m sulfur colloid was more stable than Tc-99m surface-labeled liver in vitro and its preparation was easier than with the intracellular labeling technique. Gastric emptying studies on normal subjects demonstrated equal performance of the intracellularly labeled liver and the labeled liver paté. Labeled liver paté is thus an alternative to intracellularly labeled chicken liver in measuring solid-phase gastric emptying.