Noninvasive measurement of gastric accommodation in patients with idiopathic nonulcer dyspepsia

Abstract

OBJECTIVES: Postprandial symptoms are associated with impaired postprandial gastric accommodation. The aims of this study were to apply a noninvasive method to measure accommodation of the entire stomach in healthy subjects and in patients with idiopathic dyspeptic symptoms, and to assess the frequency of abnormal gastric accommodation and emptying of solids in these patients. METHODS: In 20 healthy volunteers and 32 tertiary referral patients, we used i.v. 99mTc-single photon emission computed tomography (SPECT) to measure fasting and postprandial gastric volumes; we expressed the volume response to feeding ("accommodation") as the change in gastric volume and the ratio of postprandial/fasting volumes. The stomach was identified in transaxial SPECT tomographic images using a semiautomated, intensity-based extraction algorithm. Whole gastric volumes were measured using AnalyzeAVW software. Gastric emptying in patients was measured by scintigraphy. We also assessed dyspeptic symptoms and the association with normal or reduced accommodation. RESULTS: SPECT imaging detects the postprandial change in gastric volume ("accommodation") in health and disease. Among healthy subjects (eight men, 12 women), the postprandial/fasting gastric volume ratio was 4.9+/-1.7 (mean +/- SD; fifth through 95th percentiles 3-8, median 4.6). Thirteen (41%) patients with idiopathic nonulcer dyspepsia had reduced postprandial "accommodation." Gastric emptying was fast in four (13%), normal in 25 (78%), and slow in three (9%) patients. Both tests were normal in 50% of patients. Weight loss of >10 pounds tended to be more frequently observed in those with reduced "accommodation" (62% vs 32%, p = 0.09). CONCLUSIONS: SPECT imaging noninvasively measures fasting and postprandial gastric volumes in humans. Half the patients with idiopathic nonulcer dyspepsia had impaired gastric accommodation or emptying. Reduced gastric "accommodation" was observed in 41% of a group with idiopathic nonulcer dyspepsia. Abnormal gastric emptying is less frequent (22%).