Estimation of skin entrance dose and effective dose in neonates during common radiographic tests in public hospitals in Sari, Iran

Background and Aim: Radiography plays a crucial role in diagnosing neonatal abnormalities. Due to the heightened sensitivity of neonates to ionizing radiation, the small size of their body parts, the proximity of their organs, and their longer life expectancy, there is an increased risk of biological effects from radiation exposure. Therefore, estimating the received radiation dose in neonates is essential. This study aimed to evaluate the skin entrance dose (ESD) and effective dose in neonates admitted to the neonatal intensive care unit (NICU) from common radiographic tests. Methods: In this study, the skin entrance dose (ESD) was measured in 50 neonates in the NICU who underwent chest, abdominal, pelvic, and skull radiography. Air kerma at a distance of one meter from the X-ray tube was measured. The air kerma at the skin entrance site was then calculated, considering the distance from the tube to the film and the thickness of the anatomical region being radiographed. ESD was obtained by multiplying the air kerma by the backscatter factor. Furthermore, the effective dose was computed from the ESD using appropriate conversion factors. Results: The average ESD for chest, abdominal, pelvic, and skull radiographs were 0.3, 0.57, 0.43, and 1.01 milligray (mGy), respectively. The highest effective dose was observed in abdominal and pelvic radiography. Kilovoltage and milliampere-seconds, as the most significant factors affecting ESD, were reported to be 47.2 and 4.8 for chest radiography. The ESD values for chest and abdominal radiographs were higher than international standards, while the ESD values for skull and pelvic radiographs showed no significant difference from the diagnostic reference levels (DRL). Conclusion: The results indicate that neonates received higher doses in chest and abdominal radiographs compared to the standard thresholds. The technical conditions used in these radiographic tests, especially for chest radiography, did not align with the recommended standards. Therefore, reviewing and adjusting imaging techniques for these tests is necessary. Medical imaging centers should select exposure conditions that reduce the effective dose received by neonates while maintaining image quality. It is recommended to use high kilovoltage (kV) and low milliampere (mA) settings for radiography of the neonate's torso (chest, abdomen, and pelvis).