Simultaneous assessment of gastric accommodation and emptying: studies with liquid and solid meals.

Abstract

UNLABELLED: The aim of this study was to develop a scintigraphic test to measure gastric emptying and accommodation simultaneously. METHODS: Gastric emptying and accommodation were measured in healthy subjects. To determine gastric accommodation, the stomach was imaged with SPECT 20 min after intravenous administration of 185 MBq (5 mCi) (99m)Tc-pertechnetate. After ingestion of 11 MBq (300 micro Ci) (111)In-diethylenetriaminepentaacertic acid in a liquid nutrient drink or an (111)In-oxine-labeled egg sandwich, dual-isotope imaging assessed SPECT gastric dimensions and gastric emptying every 20 min up to 240 min. Gastric accommodation was calculated as the percentage change in planar (2-dimensional) gastric cross-sectional area (CSA) using a left anterior oblique planar projection and the percentage change in total SPECT gastric voxel counts (3-dimensional) compared with the baseline image. RESULTS: With the liquid nutrient drink (9 subjects), maximal mean CSA (158% +/- 12% of baseline; P < 0.05) occurred 40 min after meal ingestion, when only 69% +/- 3% of the radiolabeled liquid nutrient drink remained in the stomach. At 120 min, mean CSA was 125% +/- 8% of baseline, but only 35% +/- 3% of the liquid nutrient drink remained in the stomach. Using SPECT to measure 3-dimensional volumes, maximal gastric volume occurred 20 min after meal ingestion (189% +/- 25% of baseline). With the solid egg meal (10 subjects), maximal total CSA (159% +/- 13% of baseline) occurred immediately after meal ingestion; total CSA remained significantly increased above baseline for the first 3 h after ingestion of the egg meal, despite only 12% +/- 4% gastric retention at 3 h. Using SPECT to measure 3-dimensional volumes, maximal gastric volume occurred immediately after the meal (184% +/- 19% of baseline). CONCLUSION: This method permits simultaneous measurement of gastric emptying and accommodation. In healthy subjects, the gastric accommodation response is prolonged and persists despite nearly complete emptying of a liquid or solid meal.