Radiation shield for neonatal incubators: design and dosimetric evaluation in NICU radiography

Portable radiography in neonatal intensive care units (NICUs) produces scatter that can expose nearby neonates and healthcare workers, and space constraints may limit distance-based protection. This study aims to develop and validate a practical incubator-mounted shielding device and quantify its effect on scatter and projected occupational dose. A 0.5-mm Pb-equivalent sheet was shaped to fit the incubator, covered with cleanable vinyl, and secured with Velcro. Scatter was measured using a PMMA phantom with a 25.4 × 25.4 cm cross-section and 10-cm thickness at multiple angles and distances (0.5-2.0 m) for four exposure techniques (60-90 kVp) with and without shielding, including inside-incubator and adjacent-incubator scenarios. Angle-averaged dose at 1 m decreased by 92% (60 kVp/2 mAs), 86% (70 kVp/10 mAs), 85% (80 kVp/20 mAs) and 84% (90 kVp/63 mAs), with reductions consistent across angles and distances. Dual deployment further reduced scatter to adjacent incubators and nearby staff positions. Using institutional workload assumptions, projected annual occupational doses in the common-use 60 kVp/2 mAs scenario were already low at baseline and decreased by >90% with shielding, remaining <0.1 mSv/year at all tested distances. At 50 cm under this scenario, the estimate decreased from 0.034579 to 0.002871 mSv/year. User acceptance was surveyed among nurses and radiologic technologists (mean 4.59/5). This practical shielding approach provides consistent scatter reduction and may complement distance and exposure optimization in NICU radiography when space is limited.