Background: Gastric emptying scintigraphy (GES) is the gold standard technique for evaluating gastric emptying time (GET). Radiopaque marker technique (ROMT) is the gold standard for colonic transit time, but it is rarely used to quantify GET.

Objective: To compare measurement of GET between ROMT and gold standard GES.

Materials and Methods: Healthy volunteers were recruited to undergo simultaneous ROMT and GES at the largest national tertiary referral center in Thailand. A standardized solid meal of 267 Kcal was administered followed by 2 capsules containing 25 radiopaque markers (ROMs). Images of both techniques were captured at pre-established time points. Interpretation was recorded as percentage of retention (% retention) of both radionuclide substance and ROMs at each time point.

Results: Nineteen healthy volunteers (11 females) with a mean age of 38.5 ± 12.5 years, and a mean body mass index (BMI) of 22.9 ± 2.3 kg/m² were recruited. The mean percentage of retention by GES at 0.5, 1, 2, 3, and 4 hours was 92.7, 65.6, 21.3, 6.2, and 2.6, respectively. ROMT analyses revealed mean % retention at 1, 2, 4, and 6 hours of 99.6, 95.2, 48.5, and 22.1, respectively. The Spearman’s rank correlation coefficient between techniques was 0.8 (p<0.001). After excluding first-hour ROMT data, linear regression analysis revealed a correlation coefficient of 0.57 between tests (p<0.001). The interclass correlation coefficient between interpreters was 0.97.

Conclusions: A moderate correlation between ROMT and GES was demonstrated. ROMT evaluated from the second to the fifth hour can be considered in patients with gastroparesis when GES is not available.

Keywords: gastric emptying scintigraphy, gastric emptying time, measurement, radiopaque marker technique