Gastric emptying scintigraphy: Comparison of imaging times for diagnosing rapid gastric emptying, a single center experience

This study aimed to evaluate the diagnostic utility of the 30- and 60-minute imaging time points for rapid gastric emptying (RGE) using gastric emptying scintigraphy. The primary objective was to determine whether the 30-minute time point, unique to the Miami Method, provides additional diagnostic value compared to the standard 60-minute time point recommended by the National Standard Protocol. A retrospective analysis was conducted on consecutive patients who underwent gastric emptying scintigraphy between 2015 and 2021. Patients were included if they completed imaging at both 30 and 60 minutes using a hybrid protocol incorporating the Miami Method and the National Standard Protocol. The McNemar's test was used to compare the frequency of RGE diagnosis at the 30- and 60-minute time points and Cohen's Kappa coefficient to assess the inter-time point agreement. Among the 38 patients diagnosed with RGE, 24 patients (63%) were diagnosed with RGE only at 30 minutes, 6 patients (16%) were diagnosed with RGE only at 60 minutes, and 8 patients (21%) were diagnosed with RGE at both 30 and 60 minutes. The McNemar's test showed a statistically significant difference (P = .0024) between the 30- and 60-minute time points, indicating that 30-minute imaging identifies a distinct group of patients who might not be diagnosed at 60 minutes. However, there was poor agreement between the 2 time points (Cohen's Kappa = -0.34), suggesting that the 30-minute time point may need further validation. The 30-minute imaging time point detected more cases of RGE compared to the 60-minute time point, suggesting that it may capture early rapid emptying events missed at 60 minutes. However, the lack of agreement between the time points raises concerns about overdiagnosis. These findings highlight the need for further research to validate the clinical utility of the 30-minute time point and determine its impact on patient management and outcomes.