Background: The aim of this study was to investigate the effect of a standardized meal on intestinal activity in technetium 99m tetrofosmin myocardial perfusion scintigraphy.
Methods and results: The study population consisted of 60 patients (42 men and 18 women; mean age, 56 +/- 8 years) referred for myocardial perfusion imaging. All patients underwent same-day exercise-rest Tc-99m tetrofosmin single photon emission computed tomography (SPECT) imaging. All patients were given 200 mL of milk 15 minutes after the injection for the exercise SPECT study and just after the injection for the first rest SPECT study. None of the patients ate or drank between the exercise and the first rest SPECT studies. After the first rest SPECT study, 30 patients (meal group) were given a standardized meal of solid food and liquid to increase the volume of the stomach, and a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study. In 30 patients (control group) a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study, but this group did not eat or drink in this interval. The effect of the meal on intestinal activity was evaluated both visually and quantitatively. Frequency of intestinal activity was assessed visually on SPECT images. Inferior myocardial wall and abdominal activity adjacent to the myocardium was quantitatively assessed on 3 different planar projections in the rest studies, and the mean inferior wall-to-abdomen count ratio was calculated. In the meal group, inferior wall-to-abdomen count ratios in the first and second rest studies were 1.48 +/- 0.3 and 2.09 +/- 0.4, respectively (P <.0001), and in the control group, 1.41 +/- 0.2 and 1.40 +/- 0.2 (P >.05), respectively. The frequency of intestinal activity was 63% (n = 19) in the first rest SPECT study and 10% (n = 3) in the second study in the meal group (P <.0001); it was 66% (n = 20) in the first rest SPECT study and 76% (n = 23) in the second study in the control group (P >.05).
Conclusions: Our results indicate that filling of the stomach with a meal of solid food and liquid before rest acquisition may provide a high target-to-nontarget ratio. This simple modification may reduce the frequency of intestinal activity of Tc-99m-labeled radiopharmaceuticals in myocardial perfusion imaging.