RESUMO
BACKGROUND: Transthoracic echocardiography (TTE) and myocardial perfusion imaging (MPI) are used in cardiac patients. In this study the radiation exposure of sonographers performing TTE following MPI was evaluated. METHODS: Of 40 study patients, 30 underwent same-day 99mTc sestamibi MPI and TTE, while another 10 underwent only TTE. Patients who underwent both studies were divided into three groups: right-handed TTE performed by an echocardiographer and right- and left-handed TTE performed by a cardiac sonographer. Seven thermoluminescent radiation dosimeter badges monitored the forehead, wrists, anterolateral right and left chest, sternal notch, and umbilical region of each examiner. Group characteristics were compared. Radiation exposures were deemed positive if >0.1 mSv. RESULTS: There were no statistical differences in patient weight and body mass index. The left-handed approach group had higher residual radioactivity (979 ± 73 vs 884 ± 73 MBq [P < .01] and 906 ± 81 MBq [P < .04]), but no statistical difference in duration of TTE, compared with the other two MPI groups. Radiation exposure was positive in the right anterolateral chest and hand (0.45 and 1 mSv, respectively) for the echocardiographer, the right anterolateral chest and wrist and umbilical region (0.59, 1.06, and 0.15 mSv, respectively) for the right-handed sonographer, and the left chest and hand (0.12 and 0.34 mSv, respectively) for the left-handed sonographer. Dosimeters indicated no radiation exposure in the TTE-only group. CONCLUSIONS: Staff members performing TTE after MPI are exposed to radiation that might warrant monitoring. Altering study sequence, adopting a left-handed approach, and using other radiation-reducing techniques can minimize the degree of exposure.