3 May 2002 Noise properties of a Se-based flat-panel x-ray detector with CMOS readout integrated circuits
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This paper describes the noise properties of a Se-based flat-panel X-ray detector (FPD) with 128-channel CMOS readout integrated circuits (ICs). The detector used in this study is a 23 cm X 23 cm direct detection FPD utilizing a thick a-Se film. The TFT array format is 1536 X 1536 pixels with a pixel pitch of 150 micrometers . The key component of this FPD is a newly developed CMOS readout IC, which integrates 128 readout channels. Each channel consists of a charge-sensitive amplifier (CSA), a low-pass filter (LPF), a correlated double sampling circuit (CDS), and an analog sample-hold circuit. To evaluate the noise properties, theoretical noise models, including a precise expression for the CDS, were constructed and compared with the measured results, which were obtained by analyzing the noise power spectra (NPS) of the dark images taken without X-ray exposure. In addition, the detective quantum efficiency (DQE) was measured at several fluoroscopic dose ranges to demonstrate the overall signal-to-noise performance. As a result, a total readout electronic noise of 2,100 e- rms was obtained, in which thermal noise and 1/f noise of the amplifier was dominant. The DQE(0) measured was about 0.5 at 1 (mu) R.
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Susumu Adachi, Susumu Adachi, Shinya Hirasawa, Shinya Hirasawa, Masayuki Takahashi, Masayuki Takahashi, Hisao Okada, Hisao Okada, Yasukuni Yamane, Yasukuni Yamane, Satoshi Yamada, Satoshi Yamada, } "Noise properties of a Se-based flat-panel x-ray detector with CMOS readout integrated circuits", Proc. SPIE 4682, Medical Imaging 2002: Physics of Medical Imaging, (3 May 2002); doi: 10.1117/12.465603; https://doi.org/10.1117/12.465603

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