Linardatos Dionysios, Koukou Vaia, Martini Niki, Konstantinidis Anastasios, Bakas Athanasios, Fountos George, Valais Ioannis, Michail Christos
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, University of West Attica, Ag. Spyridonos, 12210 Athens, Greece.
Radiological Sciences Group, Department of Medical Physics, Queen Alexandra Hospital, Portsmouth Hospitals University NHS Trust, Portsmouth PO6 3LY, UK.
Materials (Basel). 2021 Feb 13;14(4):888. doi: 10.3390/ma14040888.
Certain imaging performance metrics are examined for a state-of-the-art 20 μm pixel pitch CMOS sensor (RadEye HR), coupled to a GdOS:Tb scintillator screen. The signal transfer property (STP), the modulation transfer function (MTF), the normalized noise power spectrum (NNPS) and the detective quantum efficiency (DQE) were estimated according to the IEC 62220-1-1:2015 standard. The detector exhibits excellent linearity (coefficient of determination of the STP linear regression fit, R was 0.9978), while its DQE peaks at 33% and reaches 10% at a spatial frequency of 3 cycles/mm, for the measured with a Piranha RTI dosimeter (coefficient of variation CV = 0.03%) exposure value of 28.1 μGy DAK (detector Air Kerma). The resolution capabilities of the X-ray detector under investigation were compared to other commercial CMOS sensors, and were found in every case higher, except from the previous RadEye HR model (CMOS-GdOS:Tb screen pair with 22.5 μm pixel pitch) version which had slightly better MTF. The present digital imager is designed for industrial inspection applications, nonetheless its applicability to medical imaging, as well as dual-energy is considered and certain approaches are discussed in this respect.
对一款与GdOS:Tb闪烁体屏幕耦合的、具有20μm像素间距的先进CMOS传感器（RadEye HR）的某些成像性能指标进行了研究。根据IEC 62220-1-1:2015标准估计了信号传输特性（STP）、调制传递函数（MTF）、归一化噪声功率谱（NNPS）和探测量子效率（DQE）。该探测器表现出优异的线性度（STP线性回归拟合的决定系数，R为0.9978），而在用食人鱼RTI剂量计测量时，其DQE在28.1μGy DAK（探测器空气比释动能）的曝光值下，在空间频率为3周期/mm时达到33%的峰值并在该频率下达到10%（变异系数CV = 0.03%）。将所研究的X射线探测器的分辨率能力与其他商用CMOS传感器进行了比较，发现除了之前的RadEye HR型号（像素间距为22.5μm的CMOS-GdOS:Tb屏幕对）版本的MTF略好外，在每种情况下该探测器的分辨率能力都更高。本数字成像器专为工业检测应用而设计，尽管如此，仍考虑了其在医学成像以及双能成像方面的适用性，并在这方面讨论了某些方法。
