Evaluation of patient effective dose in a PET/CT test.

The positron emission tomography (PET)/computed tomography (CT) technique generates high doses in patients because two radiodiagnostic modalities are used in a single examination. In this study, the absorbed and effective doses generated by CT scans and by the incorporation of radiopharmaceutical solution were evaluated in 19 organs. It was found that 78.2% of the effective dose in PET/CT examinations comes from the CT scan. With an activity of 3.33 MBq/kg-1, 18F-FDG contributes 21.8% of the final effective dose.