Cousin A J, Lawdahl R B, Chakraborty D P, Koehler R E
Department of Radiology, University of Alabama School of Medicine, Birmingham.
Invest Radiol. 1987 Aug;22(8):688-92. doi: 10.1097/00004424-198708000-00012.
Numerous eyeglass lens materials have been recommended for protection of radiologists' eyes from the cataractogenic effect of radiation during fluoroscopic procedures. For the most part, these lenses coincidentally attenuate x-ray beams because they contain elements of high atomic number that are added to increase refractive index. With a bean hardened to simulate scatter, direct transmission ratios were measured for 32 commercially available lens materials. Scatter to the eye, both through and around the glass lenses and secondary scatter to the eye from the radiologist's head, was determined with lenses mounted on a head phantom and a 1-cm3 ion chamber in the position of the eye. Transmission ratios for the various lenses ranged from 3% to 98% for an 80 kVp x-ray beam (HVL = 4.5 mm Al). Measurements with the head phantom in place show that secondarily scattered radiation from the fluoroscopist's head contributes significantly to ocular exposure. Optimal radiation protection of the eyes during fluoroscopy depends not only on eyeglasses with leaded glass, but also on shielding of sufficient size and shape to reduce exposure to the surrounding head.
众多眼镜镜片材料已被推荐用于保护放射科医生的眼睛，使其在荧光透视检查过程中免受辐射致白内障的影响。在很大程度上，这些镜片会巧合地衰减X射线束，因为它们含有添加的高原子序数元素以增加折射率。使用硬化线束模拟散射，测量了32种市售镜片材料的直接透射率。通过将镜片安装在头部模型上，并在眼睛位置放置一个1立方厘米的离子室，确定了通过玻璃镜片以及绕过玻璃镜片到达眼睛的散射，以及来自放射科医生头部对眼睛的二次散射。对于80 kVp的X射线束（半值层 = 4.5毫米铝），各种镜片的透射率范围为3%至98%。头部模型就位时的测量结果表明，荧光透视医生头部的二次散射辐射对眼部照射有显著贡献。荧光透视期间眼睛的最佳辐射防护不仅取决于含铅玻璃眼镜，还取决于足够大小和形状的屏蔽物，以减少对周围头部的照射。
