An efficient method for evaluating the lead equivalence of x‐ray radiation protective equipment using an analytical spectrum model

BACKGROUND: ), as it is a recognized standard protective value. Current methods require multiple comparative measurements with reference lead sheets, rendering the process laborious, susceptible to errors, and challenging to apply across a large medical facility with diverse protective equipment. PURPOSE: To introduce an efficient method for evaluating lead equivalence based on a computational model involving analytical spectrum modeling. METHODS: ), tube voltages (60-120 kV), and filtration (0.1-1 mm added copper). Analytical primary spectra were then matched to scatter spectra in terms of first and second tenth-value layer (TVL) thicknesses in lead. RESULTS: The method is accurate to within approximately 3% and is suitable for both narrow and broad beams. For broad beams, it is necessary to scale the measured transmission by the buildup factor for lead, as the analytical spectrum model does not account for scatter. This factor, which transfers broad-beam air kerma to narrow-beam air kerma, ranges from 1.0 to 1.5 for 50-120-kV beams incident upon lead sheets with thicknesses of 0.1-1.0 mm. Without this factor, the lead equivalence can be underestimated by up to 28%. Using the method developed, it was found that the effectiveness of lead-free aprons decreases by up to 20% for high-kV and high-filtration beams, while other equipment investigated agreed more closely with specifications. The MC simulations of scatter spectra indicated that scatter beams are generally softer than primary beams, with a reduction in TVL by up to 54% (average of 25%). The entire range of scatter-mimicking primary beams can be realized with tube voltages 50-100 kV and less than 0.3 mm added copper filtration. CONCLUSIONS: The method developed can accurately convert measured transmission into lead equivalence using a computational model, which eliminates the need to handle physical lead sheets. The transmission can be measured using recommended scatter-mimicking x-ray tube beams, derived here for a broader range of scatter angles and clinical beams with higher filtration than has previously been considered.