Assessment of Radiation Dose and Protection Practices in Neonatal Radiography in NICUs

Neonatal radiography is essential in neonatal intensive care units (NICUs) for diagnosing and monitoring critical conditions. However, the use of ionizing radiation in fragile neonates - particularly in repeated chest and abdominal x rays - raises concerns about cumulative radiation exposure and its potential long-term health effects. This study aimed to quantitatively assess the entrance surface dose (ESD) received by neonates during chest and abdominal radiography in two NICUs in Saudi Arabia and to compare with the international diagnostic reference levels (DRLs). A prospective, quantitative study of 100 neonates (50 in each hospital) on clinically justified chest and abdominal radiographs with mobile digital x-ray units was conducted. ESD was estimated from technical exposure parameters [tube voltage (kVp), milliampere-seconds (mAs), and focus-to-skin distance (FSD)] using the NRPB-recommended method. Correlation analyses and multiple linear regression were conducted to find the dose variation predictors. The average ESD was 0.48 ± 0.18 mGy in Hospital A and 0.49 ± 0.08 mGy in Hospital B with no statistically significant difference between the two hospitals. These results are well over ~5-10 times the international neonatal DRLs. ESD was significantly correlated with mAs (r=0.67) and patient thickness (r=0.76), and with kVp (r=0.54) in a moderate level of association; however, kVp and mAs were only weakly correlated (r=0.11). Regression analysis showed that patient thickness, mAs, and kVp were significant independent predictors of ESD (adjusted R2 = 0.65, p < 0.001). Neonatal radiation doses were found to be significantly elevated compared with the international reference levels, highlighting the need for immediate optimization. Dose reduction techniques like protocol standardization, elevated kVp at low mAs setting, beam collimation, and filtration must be used. These findings provide baseline data for establishing regional neonatal DRLs in Saudi Arabia and support future optimization studies using anthropomorphic phantoms.