To our knowledge, no study has reported the radiation doses of neonates admitted to neonatal intensive care units (NICUs) in Korea. Therefore, we evaluated the radiation frequency and dose of radiation performed in NICUs using mobile X-ray machines. We retrospectively analyzed the number of radiographs and doses among 290 very low-birth-weight infants (VLBWIs) admitted at our hospital between 2011 and 2016. We compared X-ray frequencies and radiation doses according to clinical characteristics and morbidities. The entrance surface doses (ESDs) were calculated using the non-dosimeter dosimetry formula. The median number of radiographs per infant was 26, and about 25% neonates had over 50 radiographs. The number of radiographs taken was higher for infants with low-birth-weight (LBW), respiratory distress syndrome, bronchopulmonary dysplasia, and longer central venous catheterization duration (p < 0.001 for all). The cumulative ESD was 0.18 to 9.89 mGy, and the ESD per radiograph was 0.049 to 0.069 mGy. The LBW and the more severe the neonates’ condition, the greater was the radiation exposure. It is difficult to reduce the number of radiographic examinations, but the quality of examinations must be improved without compromising patient care. Additional studies are needed to minimize the cumulative exposure dose and achieve optimal image quality.
