Evaluation of gastric emptying and motility in diabetic gastroparesis withmagnetic resonance imaging: Effects of cisapride

OBJECTIVE: The motor mechanisms that underlie both slow gastric emptying in diabetic gastroparesis and its acceleration by cisapride are poorly unders tood, We have recently shown that magnetic resonance imaging (MRI) allows c oncurrent evaluation of both gastric emptying and regional gastric motility . METHODS: Emptying and motility were measured in eight diabetic patients wit h previously demonstrated delayed gastric emptying using a rapid MRI techni que during oral administration of cisapride and placebo. Studies were perfo rmed in a double blind fashion and each patient acted as his own control. S ubjects were studied supine for 120 min in a 1.5 Tesla MRI scanner after in gestion of 500 mi of 10% Intralipid. Gastric emptying corrected for the vol ume of secretions was determined every 15 min using transaxial scans. Each transaxial scan was followed by 120 coronal scans at 1 s intervals. Coronal scans were angled to provide simultaneous imaging of the proximal and dist al stomach. MRI studies were also performed in seven diabetic patients with normal emptying who served as disease controls. RESULTS: Emptying was slower in the gastroparetic patients (t(1/2): 124 +/- 10 min) compared to patients with normal emptying (81 +/- 9 min, p < 0.05) . Cisapride accelerated gastric emptying (74 +/- 5 vs 124 +/- 10 min) in pa tients With gastroparesis. The contraction amplitudes in the proximal stoma ch of gastroparetic patients were increased during cisapride treatment (17. 2% +/- 1.8% vs 13.2% +/- 0.6%; p < 0.02), whereas antral contraction freque ncy, amplitude, and velocity were unchanged. CONCLUSIONS: We conclude that cisapride-induced acceleration of liquid gast ric emptying in diabetic gastroparesis does not appear to result from chang es in antral contractility, but may be related to changes in proximal gastr ic cone or gastric outlet resistance. (C) 1999 by Am. Coil. of Gastroentero logy.