Dosis de radiación y calidad de imagen en un equipo de cardiología intervencionista pediátrico

The optimized methodology and results of the new characterization in terms of dose and image quality of the x-ray system used in the main service of pediatric hemodynamics of Chile is presented. In addition, scatter dose rate values at the level of the eyes of operators in different thickness of absorbing medium and all acquisition modes available in the angiography are also presented. The characterization was performed according to the European protocols DIMOND and SENTINEL adapted to pediatric procedures. The entrance surface air kerma (ESAK) was measured and the image quality parameters signal-to-noise ratio (SNR) and a figure of merit (FOM) were calculated. The scatter dose rate was measured in units of personal equivalent dose. The ESAK for fluoroscopic modes ranged from 0.2 to 35.6 μGy/frame going from 4 to 20cm of polymethyl methacrylate (PMMA). For the cine mode, those values oscillated between 2.8 and 160.1 μGy/frame. The values of the parameters of quality of image show a correct configuration of the system, although in medium fluoroscopic mode abnormal values are observed. In terms of the scattered dose rates at the cardiologist' eye level, the highest values were for a PMMA thickness of 20cm, where cine mode reached 9.41mSv·h^-1. Differences with previous assessments can be explained by the system deterioration and by the change of one X-ray tube.