Somervaille L J, Chettle D R, Scott M C
Phys Med Biol. 1985 Sep;30(9):929-43. doi: 10.1088/0031-9155/30/9/005.
The factors affecting the accuracy and minimum detectable concentration of in vivo tibia lead measurement are discussed, and it is demonstrated that the use of a 109Cd source in a backscatter geometry and using the 88 keV coherently scattered photon for normalisation optimizes both criteria. The measurement is shown to be independent of variations in source-sample distance, thickness of overlying tissue and tibia size and shape. Applying the same technique in vitro to samples of human tibia and metatarsals, it is shown that the results are not significantly different (p approximately equal to 0.9) from atomic absorption spectrometry results from another laboratory. The results of Monte Carlo dose distribution calculations are presented and compared with measurements using thermoluminescent dosemeters: the mean absorbed dose to a 20 cm leg section is less than 0.1 mGy (10 mrad) and the maximum absorbed skin dose is 0.45 mGy (45 mrad). For this dose the minimum detectable lead concentration is 10 micrograms g-1. Finally, the technique has been applied to groups of normals and occupationally exposed workers, and the means have been shown to be significantly different, namely 10 and 31 micrograms g-1 respectively. In the normal subjects tibia lead correlated strongly with age (r = 0.63, p less than 0.001).
讨论了影响体内胫骨铅含量测量准确性和最低可检测浓度的因素，并证明在反向散射几何结构中使用(^{109}Cd)源并利用(88keV)相干散射光子进行归一化处理可优化这两个指标。结果表明，该测量与源-样品距离、覆盖组织厚度以及胫骨大小和形状的变化无关。将相同技术应用于人体胫骨和跖骨的体外样品，结果显示与另一个实验室的原子吸收光谱法结果无显著差异（(p)约等于(0.9)）。给出了蒙特卡罗剂量分布计算结果，并与使用热释光剂量计的测量结果进行了比较：对(20cm)腿部截面的平均吸收剂量小于(0.1mGy)（(10mrad)），最大吸收皮肤剂量为(0.45mGy)（(45mrad)）。对于该剂量，最低可检测铅浓度为(10)微克(g^{-1})。最后，该技术已应用于正常人和职业暴露工人组，结果显示两组均值有显著差异，分别为(10)和(31)微克(g^{-1})。在正常受试者中，胫骨铅含量与年龄密切相关（(r = 0.63)，(p\lt0.001)）。
