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Objective We evaluated intra- and interoperator reproducibilities in calculating the conventional indices HH15 and LHL15 from 99mTc-diethylenetriamine pentaacetic acid galactosyl human serum albumin (99mTc-GSA) scintigraphy, and proposed new, simple methods for the calculation of quantitative indices.

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.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.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.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.

Objective We evaluated intra- and interoperator reproducibilities in calculating the conventional indices HH15 and LHL15 from 99mTc-diethylenetriamine pentaacetic acid galactosyl human serum albumin (99mTc-GSA) scintigraphy, and proposed new, simple methods for the calculation of quantitative indices. Methods The results of 99mTc-GSA scintigraphy in 33 patients were retrospectively analyzed. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively, and HH15 and LHL15 were calculated. In addition, square regions of interest (ROIs) of fixed sizes were placed at the highest activity in blood pool and the liver. Using the square heart ROI, sHH15, an equivalent of HH15, was computed. Fractional liver uptake at 15 min (FLU15) was calculated using the square heart and liver ROIs. Intra- and interoperator reproducibilities, as well as correlation with Indocyanine green retention rate at 15 min (ICG R15), were assessed for these four indices by linear regression analysis. Results Substantial intra- and interoperator variabilities were found for HH15 and LHL15. The correlation coefficients for intra- and interoperator comparisons were 0.884 and 0.869 for HH15, respectively, and 0.919 and 0.917 for LHL15, respectively. The use of square ROIs instead of hand-drawn ROIs improved reproducibility. The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively. Correlation with ICG R15 was better for sHH15 (r = 0.619) and FLU15 (r = −0.656) than for HH15 (r = 0.439) and LHL15 (r = −0.490). Conclusions HH15 and LHL15 showed substantial intra- and interoperator variabilities, and the use of square ROIs are indicated to provide better reproducibility.