Having fasted for around four hours before the study, the patient is given a solid or semi-solid meal, such as scrambled eggs on toast or porridge, which has been prepared with a radiopharmaceutical component. Typically technetium-99m sulphur colloid or DTPA is used.[4][1][5] Some studies may also involve a liquid component, which is labelled with indium-111 DTPA.[5] Images are acquired with a gamma camera, initially dynamically and then at intervals for up to 2-3 hours.[1][5][6]
Analysis
The stomach time-activity curve is produced from geometric mean of anterior and posterior imaging. Half-emptying time, the lag-phase duration for solid studies, and percentage of food left at various time points are calculated.[7]