Use of an oral effervescent agent in the evaluation of gastric 67Ga uptake.

Objective: Gastric uptake of (67)Ga may be observed in patients with no obvious gastric lesions, as well as those with gastric malignancy. The aim of this study was to investigate whether the use of an effervescent agent aids in evaluating gastric (67)Ga uptake.

Methods: Twenty patients having or suspected of having gastric uptake on whole-body (67)Ga scintigrams were studied. Anterior abdominal images were obtained at baseline and after the oral intake of the effervescent agent (gas contrast image). The presence or absence of malignant gastric uptake was judged visually using the baseline image or gas contrast image. The judgment was compared with the clinical diagnosis, and the clinical usefulness of the gas contrast technique was assessed.

Results: In all patients, successful distension of the stomach was indicated in the gas contrast image. Clinical assessment showed gastric lesions in six patients (gastric involvement of lymphoma in 3, primary gastric lymphoma in 2, and adenocarcinoma in 1). The gas contrast image yielded accurate judgments of malignant gastric uptake in all patients except one with adenocarcinoma. Imaging after gastric distension induced by the oral effervescent agent contributed to excluding malignant gastric uptake in eight patients and demonstrating malignant gastric uptake in four patients.

Conclusions: Benign gastric uptake may complicate the assessment of gastric lesions in (67)Ga scintigraphy. Additional spot imaging after oral intake of an effervescent agent can aid in evaluating malignant gastric lesions through gastric distension.