Compton-scattering measurement of diagnostic x-ray spectrum using high-resolution Schottky CdTe detector
Compton-scattering measurement of diagnostic x-ray spectrum using high-resolution Schottky CdTe detector
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DOI：
10.1118/1.1921647
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发表时间：
2005-06-01
期刊：
影响因子：
3.8
通讯作者：
Taniguchi, A
中科院分区：
文献类型：
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作者：
Maeda, K;Matsumoto, M;Taniguchi, A
X射线光谱分析对于射线照相系统的质量保证（QA）和质量控制（QC）是重要的。本研究的目的是测量诊断X射线光谱在临床条件下使用高分辨率肖特基碲化镉探测器。在临床条件下，诊断光谱的直接测量是困难的，因为高光子注量率导致显著的探测器光子堆积。测量来自管的输出光谱的替代方式是首先测量来自给定样品的90度康普顿散射光子。有了这个设置检测器，堆积就不是问题了。从散射光谱，然后可以使用能量校正和Klein-Nishina函数来重建入射到散射样品上的实际光谱。验证我们的光谱测量的康普顿方法是准确的，通过比较计算的曝光率从重建的光谱与电离室测量的。我们使用的铝（A1）过滤的厚度范围从0到6毫米。半值层（HVLs）获得了70千伏束通过电离室测量和2.93毫米通过光谱测量为2.78毫米。对于一个100千伏的光束，我们得到3.98和4.32毫米。通过这两种技术得到的HVLs的小差异表明，康普顿散射光谱与肖特基碲化镉探测器是适合用于测量诊断X射线光谱和有用的临床X射线设备的QA和QC。(c)2005年美国医学物理学家协会。
The analysis of x-ray spectra is important for quality assurance (QA) and quality control (QC) of radiographic systems. The aim of this study is to measure the diagnostic x-ray spectra under clinical conditions using a high-resolution Schottky CdTe detector. Under clinical conditions, the direct measurement of a diagnostic spectrum is difficult because of the high photon fluence rates that cause significant detector photon pile-up. An alternative way of measuring the output spectra from a tube is first to measure the 90 deg Compton scattered photons from a given sample. With this set-up detector, pile-up is not a problem. From the scattered spectrum one can then use an energy correction and the Klein-Nishina function to reconstruct the actual spectrum incident upon the scattering sample. The verification of whether our spectra measured by the Compton method are accurate was accomplished by comparing exposure rates calculated from the reconstructed spectra to those measured with an ionization chamber. We used aluminum (A1) filtration ranging in thickness from 0 to 6 mm. The half value layers (HVLs) obtained for a 70 kV beam were 2.78 mm via the ionization chamber measurements and 2.93 mm via the spectral measurements. For a 100 kV beam we obtained 3.98 and 4.32 mm. The small differences in HVLs obtained by both techniques suggest that Compton scatter spectroscopy with a Schottky CdTe detector is suitable for measuring the diagnostic x-ray spectra and useful for QA and QC of clinical x-ray equipment. (c) 2005 American Association of Physicists in Medicine.