Radiation Exposure of Medical Staff Conducting Stress Myocardial Perfusion Imaging

Background: The myocardial perfusion stress conducted by physicians and nurses requires two imaging sessions, one during stress and the other during rest. Echocardiography is sometimes performed before delayed imaging, and medical laboratory technicians (MLTs) have similar exposure in such cases. This study was designed to investigate the radiation exposure of physicians, nurses, radiologists, and MLTs involved in thallium-201 chloride (²⁰¹TlCl) stress myocardial perfusion imaging and echocardiography, the details of which have not been reported to date. Methods: The dose rate at thallium-201 (²⁰¹Tl) was examined using a cylindrical phantom. The exposure of physicians, nurses, and radiologists involved in the ²⁰¹TlCl stress myocardial perfusion imaging was measured using pocket dosimeters, and that of the MLTs in charge of echocardiography were measured using glass-batch dosimeters. Results: The attenuation of radiation exposure from the phantom with distance was 95% at 50 cm from the center of the phantom, demonstrated that the attenuation of the exposure dose increased with distance. The exposure dose for physicians, nurses, and radiological technologists that participated in ²⁰¹TlCl stress myocardial perfusion imaging was 0.20-0.23 μSv per exam, whereas it was 6.67-10.00 μSv per exam for MLTs. Conclusion: This study measured the dose received by physicians, nurses, and radiological technologists during stress MPI and the dose received by MLTs during echocardiography. The results provided advanced knowledge for the management of dose received by medical personnel.