Abstract Background Thyroid dose reduction during brain CT scan procedures, using protective lead clothing such as lead thyroid collars were approved in the last decades. Recently, investigators have focused on applying and designing light and non-toxic shields that contain no lead. Objective This study aimed to compare the efficiency of non-lead and lead thyroid shields in radiation protection during brain CT scans based on Monte Carlo (MC) simulation and experimental measurements. Methods This study was performed in two steps. The first step was the MC simulation of a different combination of shielding materials to assess the efficiency of X-ray attenuation in these shields. The second step was the construction and testing of the shield, which was more efficient in MC calculation as a thyroid shield in brain CT scan. The absorbed dose of a Rando phantom thyroid was determined by both non-lead and lead shields as thyroid protectors. The thyroid radiation dose was measured with and without the usage of radiation shields. The percentage difference between the dose in the presence of the shield and without the shield was calculated. Result The percentage difference of the surface radiation doses on thyroid location with non-lead (combination of 45% Tungsten- 55% Tin) and lead shields in comparison to without application of the radiation shield were 35.88% and 20.73, respectively. The dose reduction at the depth of the thyroid was 39.79% and 21.49% applying non-lead and lead shields, respectively. Conclusion According to the results, the use of non-lead shield can reduce the absorbed dose of thyroid more efficiently than the lead shields.

中文翻译：

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无铅和铅甲状腺屏蔽在 CT 检查辐射防护中的效率

摘要 背景 在过去的几十年里，在脑 CT 扫描过程中减少甲状腺剂量，使用铅甲状腺衣领等铅防护服已被批准。最近，研究人员专注于应用和设计不含铅的轻质无毒防护罩。目的 本研究旨在基于蒙特卡罗 (MC) 模拟和实验测量比较无铅和有铅甲状腺屏蔽在脑 CT 扫描过程中的辐射防护效率。方法 本研究分两步进行。第一步是对屏蔽材料的不同组合进行 MC 模拟，以评估这些屏蔽中 X 射线衰减的效率。第二步是盾构的构建和测试，作为脑CT扫描中的甲状腺盾，在MC计算中更有效。Rando 幻影甲状腺的吸收剂量由作为甲状腺保护器的无铅和铅屏蔽确定。在使用和不使用辐射屏蔽的情况下测量甲状腺辐射剂量。计算有防护罩和没有防护罩时剂量之间的百分比差异。结果使用无铅（45%钨-55%锡的组合）和铅屏蔽与不使用辐射屏蔽相比，甲状腺部位表面辐射剂量的百分比差异分别为35.88%和20.73。应用无铅和铅屏蔽，甲状腺深处的剂量减少分别为 39.79% 和 21.49%。结论 结果表明，使用无铅屏蔽比铅屏蔽更能有效降低甲状腺吸收剂量。