Secondary ionizing radiation generated by analog and digital coronary cineangiographic equipment. Influence of external protection devices

Background: Exposure to ionizing radiation is a known hazard of radiologica l procedures. Aim: To compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other w ith analog image generation. To evaluate the effectiveness of external radi ological protection devices. Material and methods: Environmental and fluoro scopy generated radiation in the cephalic region of the patient was measure d during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique projection (ALO) and in anterior right oblique proje ction (ARO) were measured with and without leaded protections. In 19 patien ts (group 1), a digital equipment was used and in 21 (group 2), an analog e quipment. Results: Header radiation for groups 1 and 2 was 1194 +/- 337 and 364 +/- 222 mu Gray/h respectively (p<0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612 +/- 947 an d 70 +/- 61 mu Gray/h respectively (p<0.001). For ALO projection, generated radiation for groups 1 and 2 was 105 +/- 47 and 71 +/- 192 mu Gray/h respe ctively (p<0.001). During filming the radiation for ALO projection for grou ps 1 and 2 was 7252 +/- 9569 and 1671 +/- 2038 mu Gray/h respectively (p = 0.03). Out of the protection zone registered radiation during fluoroscopy f or groups 1 and 2 was 2800 +/- 1741 and 1318 +/- 954 mu Gray/h respectively (p < 0.001); during filming, the figures were 15500 +/- 5840 and 18961 +/- 10599 mu Gray/h respectively (NS). Conclusions: Digital radiological equip ment has a lower level of ionizing radiation emission than the analog equip ment.