Evaluation of the optimal administrated activity in gated myocardial perfusion SPECT

Prominence of radionuclide myocardial perfusion imaging (MPI) using single photon emission computed tomography (SPECT) has been investigated and shown to have high precision and predictive value. Improvement of the quality care for patients could be obtained by decreasing the radiation dose and increasing the image quality. The objective of this work is quantitative evaluation of the injected dose in MPI. 32 patients were categorized into 4 groups; each group received a different radiant dose. Image quality indices (Heart/Background (H/B), Heart/Lung (H/P) and Heart/Liver (H/L)) ratios and cardiac ejection fraction (EF%) were determined. It was observed from the images, that there is no substantial alteration in image quality among the groups. It was concluded that the most optimal dose providing the best image is the lowest one.