Radionuclide Gastric Emptying: Correlation Between the Anterior-Only and the Geometric Mean Method

Abstract

The purpose of our study was to compare the attenuation-corrected method and noncorrected method in calculating gastric emptying in patients with a clinical diagnosis of delayed emptying. Two different methods of calculating gastric emptying time were analyzed in 135 patients. Patients were given 100 ml of microwave-cooked egg whites labeled with 2.0 mCi of technetium-99m sulfur colloid and 300 ml of water. Anterior and posterior counts were obtained by a computer, interfaced to a gamma camera, with the patients in an upright position. The correlation coefficients for the 60- and 90-min data were 0.90 and 0.92, respectively. The results of the anterior-only method differed from the geometric mean method in 13% of the patients at 60 min and in 10% at 90 min. Assuming the diagnosis of delayed gastric emptying by the geometric mean method to be true, 3 of 135 patients (2.2%) at 60 min and 5 of 135 patients (3.7%) at 90 min could have been missed by the anterior method. Only 3 of 135 patients (2.2%) could have been missed by both 60- and 90-min anterior studies. The advantages of the anterior-only method may overcome the theoretical advantage of the geometric mean method in the usual clinical practice.