Tc-labelled pancake for studies of gastric emptying of solids.

To achieve a stable isotope marker of solid food, different variants of isotope-labelled Swedish pancake were tested. The marker stability was investigated by a new method assumed to test both the affinity of the isotope complex to the test meal and the mechanical stability. The test procedure included use of a gamma camera and human gastric juice. Pancakes labelled with either pertechnetate, 99TcmO4 (Tc-pert), or 99Tcm-macroalbumin aggregates (Tc-MAA) were compared. The results showed a significant difference (P less than 0.01), with 91.4 +/- 2.1% (mean +/- 1 S.D.) of activity remaining in the Tc-MAA pancake (n = 5) and only 81.1 +/- 5.8% in the Tc-pert pancake (n = 6) after 3 h. Pancakes labelled with Tc-MAA were also compared with chicken liver labelled in vivo with 99Tcm-sulphur colloid (Tc-SC). The results revealed significantly better marker stability (P less than 0.05) of pancakes compared to chicken liver, with 83.0 +/- 9.1% remaining in the Tc-MAA pancake (n = 8) and 74.9 +/- 6.7% in the Tc-SC chicken liver (n = 8) after 180 min.