Simplified scintigraphic methods for measuring gastrointestinal transit times

To investigate whether simple transit measurements based on scintigraphy pe rformed only 0, 2, 4 and 24 h after intake of a radiolabelled meal can be u sed to predict the mean transit time values for the stomach, the small inte stine, and the colon, a study was conducted in 16 healthy volunteers. After ingestion of a meal containing (111)indium-labelled water and (99m)technet ium-labelled omelette, imaging was performed at intervals of 30 min until a ll radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small intes tinal and colonic mean transit times were calculated for both markers and c ompared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Hig hly significant correlations were found between gastric mean transit time a nd fractional gastric emptying at 2 h (In-111: r = 0.95, P < 0.00001; Tc-99 m: r = 0.96, P < 0.00001), between small intestinal mean transit time and f ractional colonic filling at 4 h (In-111: r = -0.97, P < 0.00001; Tc-99m: r = -0.89, P < 0.00001), and between colonic mean transit time and geometric centre of colonic content at 24 h (In-111: r = - 0.88, P < 0.00001). We th erefore conclude that reliable regional gastrointestinal transit times can be estimated from scintigraphic images taken 0, 2, 4 and 24 h after intake of radiolabelled markers.