Gastric motility and emptying assessment by magnetic resonance imaging after lung transplantation: correlation with gastric emptying scintigraphy

Purpose: Gastroparesis is a frequent gastrointestinal complication after lung transplantation. Although gastric emptying scintigraphy (GES) is the standard technique to evaluate gastroparesis, magnetic resonance imaging (MRI) can also assess gastric motility and emptying. This study compared the results obtained by these two modalities. Methods: Twenty-two lung transplant recipients underwent MRI and GES after ingesting a small pancake as a test meal. Parameters assessed on MRI included antral peristaltic wave velocity and frequency, and the ratios of gastric content volume at 15 and 35 min. GES parameters included retention rates (RR) in the stomach at 30, 60, and 120 min (RR30, RR60, and RR120) and half-time of emptying (T1/2) calculated by exponential curve fitting. Correlations between MRI and GES results were evaluated. Results: Peristaltic wave velocity showed significant moderate negative correlations with RR120 (r = - 0.58, p < 0.05) and T1/2 (r = - 0.60, p < 0.05), indicating an association between reduced velocity and prolonged gastric emptying. Gastric content volume ratios on MRI showed significant moderate positive correlations with RR30 (r = 0.46, p < 0.05), RR60 (r = 0.60, p < 0.01), and T1/2 (r = 0.60, p < 0.01). There were no significant correlations between peristaltic wave frequency and GES parameters. MRI and GES parameters did not differ significantly between the six patients with and the 16 without upper gastrointestinal symptoms. Conclusions: MRI-based determinations of gastric motility and gastric emptying correlate with GES-based gastric emptying in lung transplant recipients, suggesting that MRI is useful for evaluating patients with gastroparesis.