Analysis of radiation dose to operators involved in coronary angiography with radiation protection shields: a phantom study

Objective To measure the dose to the primary operator and assistant operators by employing eight beam projections commonly used in coronary angiography with and without radiation protection shields in order to supply helpful guidance on radiation protection in cardiac intervention. Methods From 20 to 180 cm above the ground at the primary and assistant operators' locations, a DoseAware personal dose meter was placed in terms of an increment of 20 cm to measure radiation dose. Eight commonly used beam projections were performed, including LAO (left anterior oblique) 45°, RAO (right anterior oblique) 30°, CRAN (cranial)25°, cranial LAO (LAO45°/25°), caudal LAO(LAO45°/25°), CAUD(caudal)25°, cranial RAO(RAO30°/25°), caudal RAO (caudal RAO30°/25°). Under the two different conditions, with or without radiation protection shields, the doses to the operators in the selected beam projections were respectively recorded at nine measuring positions and the shielding factor were calculated. Results The primary operator was effectively protected with radiation protection shields. In the standing area of the primary operator, except for the position at the height of 120 cm (radiation dose rate: 0.35-4.78 mSv/h; shielding factor: 27.67%-89.33%), the shielding factor for each measuring position was above 91%. Higher radiation doses were found at caudal LAO, LAO, and cranial LAO. The shielding factor for the assisting operator was lower than for the primary operator. In the standing area of the assisting operator (radiation dose rate: 0.27-1.86 mSv/h; shielding factor: 30.34%-92.13%), the peak levels were found at the height of 80, 100, 140 cm. And caudal RAO, caudal LAO, CRAN, LAO were found to have received higher radiation doses. Conclusions Emphasis should be attached to the use of radiation shields in coronary angiography. With radiation protection shields, higher dose is still recorded in caudal LAO, LAO, cranial LAO, caudal RAO. Furthermore, it should be paid more attention to radiation protection at 80-140 cm height, and less prolonged exposure should be employed in those beam projections mentioned above. Key words: Coronary angiography; Radiation dose; Radiation protection