Reproducibility of gastric emptying assessed with scintigraphy in patients with upper GI symptoms

The reproducibility of gastric emptying (GE) measured with scintigraphy in patients is poorly understood. Our aims were to assess the intra and inter-individual reproducibility of these parameters in patients with upper gastrointestinal symptoms.

Sixty patients (21 diabetics, 39 non-diabetics) with upper gastrointestinal symptoms underwent scintigraphic-assessment of GE of a solid meal (296 kcal, 30% fat) over 4 hours on two occasions at an average interval of 15 days. The concordance correlation coefficient (CCC), intra and inter-individual coefficients of variation (COV) of GE endpoints were analyzed.

The GE t_1/2 was 134 ± 8 minutes (mean ± SEM) for the first and 128 ± 6 minutes for the second study. The mean (95% CI) CCC between the two studies was 0.79 (0.67, 0.87) for GE at 1 hour, 0.83 (0.75, 0.9) for GE at 2 hours, 0.54 (0.34, 0.7) for GE at 4 hours, and 0.79 (0.68, 0.86) for GE t_1/2 . However, in 18 of 60 patients (30%), the characterization of GE as normal, delayed, or rapid differed between the first and second studies. For gastric empting t_1/2 , the inter-individual coefficients of variation was 40%; the intra-individual COV was 20%, comparable in diabetics and non-diabetics, and greater in patients with rapid (28%) than delayed (18%) or normal GE (12%).

Among patients with upper gastrointestinal symptoms, GE measured with scintigraphy is relatively reproducible. In 30% of cases, the interpretation was different between the two assessments. Hence, a diagnosis of gastroparesis based on a single study may occasionally be inaccurate.