A theoretical investigation of spectra utilization for a CMOS based indirect detector for dual energy applications

4th International Conference on Mathematical Modeling in Physical Sciences

物理学;数学

Kalyvas, N.^1 ; Martini, N.^2 ; Koukou, V.^2 ; Michail, C.^1 ; Sotiropoulou, P.^2 ; Valais, I.^1 ; Kandarakis, I.^1 ; Fountos, G.^1

Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational, Institute of Athens, Egaleo, Athens

122 10, Greece^1

Department of Medical Physics, Medical School, University of Patras, Patras

265 00, Greece^2

关键词: Coefficient of variation;    Detective quantum efficiency;    Digital mammography;    Dual-energy imaging;    Microcalcifications;    Phosphor materials;    Phosphor screens;    Theoretical investigations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/633/1/012095/pdf
DOI  :  10.1088/1742-6596/633/1/012095

来源: IOP

【 摘 要 】

Dual Energy imaging is a promising method for visualizing masses and microcalcifications in digital mammography. Currently commercially available detectors may be suitable for dual energy mammographic applications. The scope of this work was to theoretically examine the performance of the Radeye CMOS digital indirect detector under three low- and high-energy spectral pairs. The detector was modeled through the linear system theory. The pixel size was equal to 22.5μm and the phosphor material of the detector was a 33.9 mg/cm2Gd2O2S:Tb phosphor screen. The examined spectral pairs were (i) a 40kV W/Ag (0.01cm) and a 70kV W/Cu (0.1cm) target/filter combinations, (ii) a 40kV W/Cd (0.013cm) and a 70kV W/Cu (0.1cm) target/filter combinations and (iii) a 40kV W/Pd (0.008cm) and a 70kV W/Cu (0.1cm) target/filter combinations. For each combination the Detective Quantum Efficiency (DQE), showing the signal to noise ratio transfer, the detector optical gain (DOG), showing the sensitivity of the detector and the coefficient of variation (CV) of the detector output signal were calculated. The second combination exhibited slightly higher DOG (326 photons per X-ray) and lower CV (0.755%) values. In terms of electron output from the RadEye CMOS, the first two combinations demonstrated comparable DQE values; however the second combination provided an increase of 6.5% in the electron output.