Zananiri F A, Speller R D
Department of Medical Physics and Bioengineering, University College Hospital, University of London, UK.
J Biomed Eng. 1990 May;12(3):239-47. doi: 10.1016/0141-5425(90)90048-r.
The aim of this study was to investigate dual energy (DE) systems using X-ray films and intensifying screens as detecting media. This has been studied using both experimental methods and numerical modelling. Numerical methods were used to calculate energy losses due to K-fluorescent escape originating from the phosphors of the intensifying screens. This enabled the calculation of absorbed energy in screens. The method for screen selection and prediction of performance used the fact that detector response depends upon impinging X-ray energy. By equating the detector's absorbing characteristics to the resultant optical density (OD), an absorbed energy constant was calculated. These constants were used to predict OD for a given X-ray spectrum and hence simulation of detector characteristics. Experimental techniques were used to investigate sensitivity to chemical composition changes. These results compared favourably with computed values. It was demonstrated that although limitations exist, detector simulations are valid and X-ray film intensifying screen combinations make adequate DE detectors.
本研究的目的是调查使用X光胶片和增感屏作为探测介质的双能（DE）系统。这一研究采用了实验方法和数值模拟两种方式。数值方法用于计算因增感屏磷光体产生的K荧光逃逸而导致的能量损失。这使得能够计算增感屏中的吸收能量。增感屏选择和性能预测方法利用了探测器响应取决于入射X射线能量这一事实。通过将探测器的吸收特性与所得光学密度（OD）相等，计算出吸收能量常数。这些常数用于预测给定X射线光谱的OD，从而模拟探测器特性。实验技术用于研究对化学成分变化的敏感性。这些结果与计算值相比具有优势。结果表明，尽管存在局限性，但探测器模拟是有效的，并且X光胶片增感屏组合可构成足够的双能探测器。
