Atkins H L, Fairchild R G, Robertson J S, Greenberg D
Radiology. 1975 May;115(2):431-7. doi: 10.1148/115.2.431.
The spectra of diagnostic x-ray beams were measured with a germanium semiconductor dectector. With this system it was possible to define the K-alpha-1, K-alpha-2, K-beta-2 characteristic peaks of the tungsten target. The effects of various filters on the beam using characteristic absorption edges to create a "bandpass" effect were studied. Gadolinium filtration of the diagnostic beam used for contrast studies selectively removed both higher energy photons (greater than 50 keV) and lower energy photons (less than 33 keV) thus enhancing contst for iodine and barium while substantially reducing radiation dose.
使用锗半导体探测器测量了诊断用X射线束的光谱。利用该系统能够确定钨靶的K-α-1、K-α-2、K-β-2特征峰。研究了各种滤光片利用特征吸收边对光束产生“带通”效应的影响。用于造影研究的诊断束的钆滤过选择性地去除了较高能量光子（大于50keV）和较低能量光子（小于33keV），从而增强了碘和钡的造影效果，同时大幅降低了辐射剂量。
