Evaluation of Radiation Dose in Close Proximity to the Patients after Myocardial Perfusion Scan and Related Factors

We measured radiation emission from the patients undergoing myocardial perfusion scan after leaving nuclear medicine department to demonstrate how much radiation hospital staff or patients’ companions, in the vicinity of the patients would receive. We also evaluated the relationship of age, sex, and body mass index with the emitted radiation rate.

In this study 60 patients (41 females and 19 males) after undergoing 99mTc-sestamibi myocardial perfusion scan with a dose of 925±185 MBq, were selected randomly. The equivalent dose rate at distances of 0.25 m, 1 m and 2 m from the patients were measured by a survey meter before leaving nuclear medicine department and after 12 & 24 hours. Data were analyzed by T-test, Pearson correlation coefficient and ANOVA.

The mean equivalent dose rates in unit of microsievert per hour at distances of 0.25 m, 1 m and 2 m from the patients were (120.6 ± 24.1, 19.4 ± 3.8, 8.4 ± 1.3) at leaving time, (29.1 ± 8.7, 5.3 ± 1.2, 2.1 ± 0.8) after 12 hours and (4.3 ± 1.5, 0.8 ± 0.6, 0.3 ± 0.1) after 24 hours, respectively. The mean equivalent dose rate showed no relationship with gender and age, but it was inversely correlated with body mass index (P-value <0.05) after 24 hours.

People would receive reasonably low radiation if they keep a distance of at least 1 meter from the patients or stay only for a few minutes in the vicinity of the patients. After 24 hours, equivalent dose rate was inversely correlated with body mass index.