X-ray Performance Evaluation of the Dexela CMOS APS X-ray Detector Using Monochromatic Synchrotron Radiation in the Mammographic Energy Range
X-ray Performance Evaluation of the Dexela CMOS APS X-ray Detector Using Monochromatic Synchrotron Radiation in the Mammographic Energy Range
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DOI：
10.1109/tns.2013.2276123
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发表时间：
2013-10-01
影响因子：
1.8
通讯作者：
Olivo, Alessandro
中科院分区：
文献类型：
--
作者：
Konstantinidis, Anastasios C.;Szafraniec, Magdalena B.;Olivo, Alessandro
基于互补金属氧化物半导体（CMOS）有源像素传感器（APS）技术的数字探测器最近已被引入许多科学应用中。这项工作的重点是在低能量医学成像应用中使用单色同步辐射（即，17-35 keV），这也允许研究性能如何随能量变化。CMOS传感器耦合到铊激活的结构化碘化铯（CsI：Tl）闪烁体和探测器的X射线性能进行评估的灵敏度，预调制传递函数（pMTF），归一化噪声功率谱（NNPS）和由此产生的探测量子效率（DQE）。蒙特卡罗模拟被用来验证实验测量的低频DQE。最后，评价了碘的二次产生的K-荧光X射线对pMTF和DQE结果的影响。良好的协议（5%以内）之间观察到的Monte Carlo和实验测量的低频DQE的结果。CMOS APS探测器首次在覆盖乳房X线摄影光谱的宽范围低能量下进行了表征。探测器的性能主要受闪烁体的可探测性的限制。最后，我们表明，目前的数据可用于计算探测器的pMTF，NNPS和DQE的任何乳房X线摄影光谱形状内的调查能量。
Digital detectors based on complementary metaloxide-semiconductors (CMOS) active pixel sensor (APS) technology have been introduced recently in many scientific applications. This work is focused on the X-ray performance evaluation of a novel CMOS APS detector in low energy medical imaging applications using monochromatic synchrotron radiation (i.e., 17-35 keV), which also allows studying how the performance varies with energy. The CMOS sensor was coupled to a Thallium-activated structured cesium iodide (CsI:Tl) scintillator and the detector's X-ray performance evaluation was carried out in terms of sensitivity, presampling modulation transfer function (pMTF), normalized noise power spectrum (NNPS) and the resulting detective quantum efficiency (DQE). A Monte Carlo simulation was used to validate the experimentally measured low frequency DQE. Finally, the effect of iodine's secondary generated K-fluorescence X-rays on pMTF and DQE results was evaluated. Good agreement (within 5%) was observed between the Monte Carlo and experimentally measured low frequency DQE results. A CMOS APS detector was characterized for the first time over a wide range of low energies covering the mammographic spectra. The detector's performance is limited mainly by the detectability of the scintillator. Finally, we show that the current data could be used to calculate the detector's pMTF, NNPS and DQE for any mammographic spectral shape within the investigated energies.