The Reproducibility of (99m)Tc-Pertechnetate Single Photon Emission Computed Tomography (SPECT) for Measurement of Gastric Accommodation in Healthy Humans: Evaluation of the Test Results Performed at the Same Time and Different Time of the Day

BACKGROUND/AIMS: Technetium-99m ((99m)Tc)-pertechnetate single photon emission computed tomography (SPECT) allows non-invasive measurement of gastric accommodation (GA) and has been reported to provide the results comparable to the gold standard barostat. The reproducibility of the test when it is performed at different time of the day is not known. The aim of this study was to assess the reproducibility of GA measurement by (99m)Tc-pertechnetate SPECT at the same and different time of the day. METHODS: Three GA studies were performed in each of 20 healthy volunteers (9 males, age 35 ± 9 years), 2 studies in the morning and 1 study in the afternoon. Each study was performed on separate days at least 3 days apart, in random order. The fasting gastric scintigraphy images were acquired using SPECT at 30 minutes after iv (99m)Tc-pertechnetate. Then, the scintigraphic images were acquired 50 minutes after liquid meal (250 mL, Ensure®) ingestions. Gastric volumes were calculated from transaxial gastric images using Image J software. The GA was defined as the maximum postprandial gastric volume minus fasting gastric volume. RESULTS: GA measurement by SPECT show good reproducibility at both the same and different time of the day. The intraclass correlation coefficients of GA results for the same time, the first different time and the second different time studies were 0.681, 0.630 and 0.774, respectively, and the intra-subject coefficients of variation were 13.9%, 14.1% and 8.7%, respectively. CONCLUSIONS: GA measurement by (99m)Tc-pertechnetate SPECT shows good reproducibility at both the same and different time of the day. This result suggests that the schedule time does not appear to extremely affect the gastric accommodation value.