A microbeam grazing-incidence approach to L-shell x-ray fluorescence measurements of lead concentration in bone and soft tissue phantoms.
A microbeam grazing-incidence approach to L-shell x-ray fluorescence measurements of lead concentration in bone and soft tissue phantoms.
复制标题
一种微束掠入射方法，用于测量骨骼和软组织模型中铅浓度的 L 壳 X 射线荧光测量。
DOI：
10.1088/1361-6579/aaad5a
复制
发表时间：
2018
影响因子：
3.2
通讯作者：
Al-Hamdani,Summer
中科院分区：
文献类型：
--
作者：
Gherase,MihaiRaul;Al-Hamdani,Summer
贝壳X射线荧光（LXRF）是一种非侵入性的方法来测量人体骨骼中的铅（Pb）浓度。第一批研究发表于20世纪80年代初。在同一时期，开发了使用Cd-109放射性核素源的K壳层X射线荧光（KXRF）方法，后来又加以改进和完善。与LXRF方法相关的较低灵敏度和校准困难导致KXRF成为体内人骨铅研究中最常用的方法。在本研究中，一个基于微束掠入射的铅LXRF测量方法进行了调查。ApproachThe微束产生的集成X射线管和多毛细管X射线透镜（PXL）单元被用来激发圆柱形石膏的巴黎（poP）骨幻影掺杂铅在七个浓度：0，8，16，29，44，59，和74 μg g g− 1。用聚甲醛（POM）塑料制作了两个1 mm和3 mm厚的圆柱壳软组织模型。得到了对应于0、1和3 mm POM厚度值的三个骨-软组织体模集。将每个体模放置在微束和检测器之间;使用定位台控制其位置。采用小步长（0.1-0.5 mm）和短30 s X射线光谱采集，根据观察到的最大Sr Kα峰高找到最佳体模位置。在最佳几何结构下，为每个体模集采集5个180 s X射线光谱。主要结果铅的最低检出限（DL）分别为（2.9±0.2）、（4.9±0.3）和（23±3）μg g− 1。在POM塑料的180 s辐照的吸收辐射剂量的数量级估计为< 1 mGy.SignificanceThe结果是上级相对最近发表的LXRF幻影研究，并显示在体内LXRF测量的未来设计的承诺。
ObjectiveL-shell x-ray fluorescence (LXRF) is a non-invasive approach to lead (Pb) concentration measurements in the human bone. The first studies were published in the early 1980s. In the same period the K-shell x-ray fluorescence (KXRF) method using a Cd-109 radionuclide source was developed and later improved and refined. Lower sensitivity and calibration difficulties associated with the LXRF method led the KXRF to be the most adopted method for in vivo human bone Pb studies. In the present study a microbeam-based grazing-incidence approach to Pb LXRF measurements was investigated.ApproachThe microbeam produced by an integrated x-ray tube and polycapillary x-ray lens (PXL) unit was used to excite cylindrical plaster-of-Paris (poP) bone phantoms doped with Pb in seven concentrations: 0, 8, 16, 29, 44, 59, and 74 µg g− 1. Two 1 mm-and 3 mm-thick cylindrical shell soft tissue phantoms were made out of polyoxymethylene (POM) plastic. Three bone-soft tissue phantom sets corresponding to the 0, 1, and 3 mm POM thickness values resulted. Each phantom was placed between the microbeam and the detector; its position was controlled using a positioning stage. Small steps (0.1–0.5 mm) and short 30 s x-ray spectra acquisitions were used to find the optimal phantom position according to the maximum observed Sr Kα peak height. At the optimal geometry, five 180 s x-ray spectra were acquired for each phantom set. Calibration lines were obtained using the fitted peak heights of the two observed Pb Lα and Pb Lβ peaks.Main resultsThe lowest detection limit (DL) values were (2.9±0.2),(4.9±0.3), and (23±3) µg g− 1, respectively. The order of magnitude of the absorbed radiation dose in the POM plastic for the 180 s irradiation was estimated to be< 1 mGy.SignificanceThe results are superior to a relatively recently published LXRF phantom study and show promise for future designs of in vivo LXRF measurements.