Experimental evaluation of a-Se flat-panel X-ray detector for digital radiography

In this paper, the evaluation of a selenium-based flat-panel digital X-ray detector is described. The prototype detector has a pixel pitch of 139 mum and a total active imaging area of 14 inches times 8.5 inches, making up a total of 3.9 million pixels. Several quantitative parameters have been devised that correlate with the abilities of imaging devices to perform clinical tasks. The concepts of MTF, NPS, and DQE have been well described and are very useful descriptors of resolution, noise, and signal-to-noise ratio transfer ability. Such parameters (sensitivity, leakage current, MTF, NPS, DQE) were examined to evaluate the performance of this system. The sensitivity of 4.82 nC/mR/cm
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was measured at 10 V/mum, while leakage current was measured at 270 pA/cm
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. The measured MTF at 2 lp/mm was 40%, and the DQE at 1.5 lp/mm was 16%