Radiation Exposure to the Personnel Performing Myocardial Blood Flow Quantification Study Using 13N-ammonia Positron Emission Tomography/Computed Tomography

Purpose: The present study aimed to evaluate radiation exposure to staff performing coronary flow reserve (CFR) measurement using 13N-ammonia. Materials and Methods: The radiation exposure rate during the administration of 13N-ammonia for the rest and stress part of the study was noted using an ionization chamber-based calibrated survey monitor. The radiation exposure to persons involved in dispensing radioactivity (D1), administering radioactivity (D2) and monitoring the patient during pharmacological stress (D3) were measured using an energy compensated Si-diode personal pocket dosimeter. Results: The average dose received by individuals with dosimeters D1, D2, and D3 was 1.28 ± 0.79 μSv, 1.56 ± 0.51 μSv, and 0.88 ± 0.97 μSv per injection, respectively, during the rest of study and 1.56 ± 0.96 μSv, 2.64 ± 1.22 μSv, and 2.2 ± 1.7 μSv per injection, respectively, during stress study. The average exposure rate during the administration of 13N-ammonia at 0.5 m and 1.5 m from the injection site was found to be 259 μSv/h and 53.4 μSv/h, respectively, during the rest study and 301 μSv/h and 67.25 μSv/h, respectively, during stress study. Conclusion: The exposure to the staff performing CFR study with 13N-ammonia was well within prescribed limits by the International Commission on Radiological Protection 103. The CFR measurement with 13N-ammonia positron emission tomography/computed tomography can be included in routine workups of cardiac patients without the fear of radiation exposure.