EVALUATION OF AN INEXPENSIVE SCREENING SCINTIGRAPHIC TEST OF GASTRIC-EMPTYING

Our goal was to study the accuracy of a limited assessment relative to the traditional and obtain a more detailed approach to measure gastri c emptying. Methods: We prospectively evaluated 35 patients referred t o our laboratory with suspected fast or slow gastric emptying. Transit was measured radioscintigraphically after ingestion of an egg meal co ntaining Tc-99m-Amberlite pellets. Gastric emptying was analyzed by po wer exponential analysis. Diagnostic accuracy of simpler indices (gast ric residual at 2 and 4 hr) was determined by comparing the categoriza tion of patients as normal or abnormal relative to previously publishe d normal data from our laboratory. Results: Gastric residual at 2 hr s howed greater diagnostic accuracy for accelerated gastric emptying wit h 90% sensitivity at 90% specificity. Gastric residual at 4 hr was les s accurate for accelerated emptying, but was more accurate at detectin g delayed gastric emptying with 100% sensitivity at 70% specificity. I n contrast, sensitivity and specificity of gastric residual at 2 hr fo r slow emptying were low (100% sensitivity with 20% specificity) empha sizing the importance of obtaining a scan later than 2 hr for detectin g delayed gastric emptying. Conclusion: Selective scans taken at 2 and 4 hr provide an excellent screening test for detecting fast or slow g astric emptying; the accuracy of 2-hr data is optimal for accelerated emptying and that of the 4-hr data greater for delayed emptying. This strategy provides a simple, less expensive way to evaluate gastric emp tying in clinical practice with acceptable sensitivity and specificity as an initial test for patients with clinically suspected gastric sta sis or dumping syndromes.