Comprehensive Radionuclide Esophagogastrointestinal Transit Study: Methodology, Reference Values, and Initial Clinical Experience

A radionuclide methodology and reference values have been developed for a single gastrointestinal transit study including esophageal transit, liquid and solid gastric emptying, and small-and largebowel transit, using In-111-diethylenetriaminepentaacetic acid (DTPA) with the standardized Tc-99m-labeled solid meal. Methods: Eighteen healthy subjects and 18 patients were investigated. The esophageal transit study was performed with 3.7 MBq (0.1 mCi) of In-111-DTPA in 15 mL of water. A liquid-only 30-min gastric-emptying study followed, with ingestion of 3.7 MBq (0.1 mCi) of In-111-DTPA in 300 mL of water. Then, a simultaneous solid-liquid emptying study was acquired after ingestion of a solid Tc-99m-sulfur colloid-labeled meal and 7.4 MBq (0.2 mCi) of In-111-DTPA in 120 mL of water. Images were acquired intermittently for 4 h. Additional 111In images were acquired at 5 and 6 h to measure small-bowel transit, and at 24, 48, and 72 h for largebowel transit. Results: Reference values were determined for esophageal transit (transit time, percentage emptying at 10 s), liquid-only gastric emptying (emptying half-time), liquid and solid emptying in a dual-phase solid-liquid study (emptying half-time and percentage emptying at 1, 2, 3, and 4 h), small-bowel transit index (percentage transit to ileocecal valve at 6 h), and colonic transit (geometric center and percentage colonic emptying) at 24, 48, and 72 h. Results from the first 18 patients found abnormal transit in 72% (13/18); clinical management changed in 61% (11/18). Conclusion: We have developed a radionuclide methodology and derived reference values for a comprehensive gastrointestinal transit study using In-111-DTPA with the standardized Tc-99m-labeled solid meal. Our initial clinical experience suggests clinical value.