CONTROL OF RADIATION EXPOSURE TO PAEDIATRIC PATIENTS AT CONVENTIONAL RADIOLOGY AND CARDIAC CENTERS AT DUBAI HOSPITAL

In view of increasing the number of x-ray examinations over the years, paediatric radiation safety is considered as one of the critical subjects in the modern medical imaging. Paediatric patients are at higher risk from ionizing radiation than adults if they receive same amount of dose. This project was conducted to evaluate paediatric patient radiation dose levels in digital radiology (both fixed and mobile x-ray units) and interventional cardiology at Dubai Hospital. The results of this study are expected to contribute in establishing local and national diagnostic reference levels in United Arab Emirates (UAE). A combination of phantom studies and patient data collection were utilized in this paediatric dosimetry project. The patient data collection was obtained through both manual contributions from radiographers and data obtained from Digital Imaging and Communications in Medicine (DICOM) header. The first method was performed using Polymethyl methacrylate phantom with different thicknesses to represent different age groups of paediatrics; whereas the second method was without phantom where the exposure factors extracted from DICOM header. Then, effective dose was estimated using Monte Carlo dose calculation software. The primary measured and estimated radiation dose quantity was the incident air kerma. The entrance surface air kerma was calculated from the incident air kerma and then executed with the application of appropriate backscatter factors. For the fixed x-ray machine, the radiation dose levels were lower than the recommended values and other published data while for the mobile x-ray the findings were comparable and slightly higher than other surveyors. In interventional cardiology, the radiation dose values were higher compared to other values shown in previous researches. The variation in entrance skin air kerma values between the published data and the findings in this study are related to the use of different equipment, exposure parameters and it is significantly related to the professional awareness towards ionizing radiation hazards. Evidently, the values of effective doses showed that the radiation risk is higher with small ages. In UAE, this study is considered as one of the first structured studies performed on paediatric dosimetry. Further researches are needed to include image viii quality assessment to stress on obtaining optimum image quality with lower radiation dose