Radiation dose and image quality in a pediatric interventional cardiology team

Abstract

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 pediatric hemodynamics service in Chile are presented. In addition, scattered dose rate values at the operator’s eye level are reported for all acquisition modes available in different thicknesses of absorbent media and angiography. The characterization was performed according to the European DIMOND and SENTINEL protocols adapted to pediatric procedures. The air kerma at the entrance surface (ESAK) was measured and the image quality parameters signal-to-noise ratio (SNR) and a figure of merit (FOM) were calculated. The scattered dose rate was measured in personal dose equivalent units. The ESAK for fluoroscopic modes ranged from 0.2 to 35.6 μGy/image when passing from 4 to 20 cm of polymethyl methacrylate (PMMA). For the cine mode, these values ranged from 2.8 to 160.1 μGy/image. The values of the image quality parameters showed a correct system configuration, although abnormal values were observed in the medium fluoroscopic mode. As for the scattered dose rate at the level of the cardiologist’s eyes, the highest value is PMMA with a thickness of 20 cm, where the cine mode reached 9.41 mSv·h-1. The differences found from previous evaluations can be explained by the deterioration of the system and the change of one of the X-ray tubes.