Simplified scintigraphic methods for measuring gastrointestinal transit times

To investigate whether simple transit measurements based on scintigraphy performed only 0, 2, 4 and 24 h after intake of a radiolabelled meal can be used to predict the mean transit time values for the stomach, the small intestine, and the colon, a study was conducted in 16 healthy volunteers. After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time and fractional gastric emptying at 2 h (111In: r=0.95, P<0.00001; 99mTc: r=0.96, P<0.00001), between small intestinal mean transit time and fractional colonic filling at 4 h (111In: r=-0.97, P<0.00001; 99mTc: r=-0.89, P<0. 00001), and between colonic mean transit time and geometric centre of colonic content at 24 h (111In: r=- 0.88, P<0.00001). We therefore 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.