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

Abstract

Background: 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.

Methods: 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.

Results: 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%).

Conclusions & inferences: 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.

Keywords: diabetes mellitus; gastric emptying; gastroparesis; reproducibility; scintigraphy.

Figure 1

Day-to-day reproducibility of gastric emptying at 1 hour (top left), 2 (top right), 4 hours (bottom left) and gastric emptying t1/2 (bottom right). Observe excellent agreement at all time points. Participants in which the overall interpretation (i.e., as normal, rapid, or delayed GE) was different between the first and second studies are depicted with filled markers. The range of normal values in the first study are depicted by the rectangular areas outlined by dotted red (in women) and blue lines (in men). During the first study, GE1 was accelerated in 14 participants, GE2 was accelerated in 13 and delayed in 8 participants, and GE4 was delayed in 16 participants

Figure 2

Bland-Altman plots for gastric emptying reproducibility at 1 hour (top left panel), 2 hours (top right panel), 4 hours (bottom left panel) and gastric emptying t1/2 (bottom right panel). The red interrupted lines show the limits of agreement for 1 standard deviation.