Signal and noise analysis of a metal oxide transistor-based flat-panel detector

Abstract

Abstract Recently, metal-oxide thin-film transistor (TFT)-based flat-panel x-ray detectors have attracted attention owing to their fast readout times and low noise characteristics. We empirically analyzed the signal and noise characteristics of an indium gallium zinc oxide (IGZO) TFT-based detector in comparison with those of a conventional hydrogenated amorphous silicon (a-Si:H) TFT-based detector. We compared the large-area signal transfer functions of the detectors as a function of air kerma at their entrance surfaces. Signal and noise performances were evaluated by measuring the modulation-transfer function, noise-power spectrum, and detective quantum efficiency (DQE). The low-dose imaging capability of the detectors was assessed by investigating the large-area or zero-frequency DQE as a function of air kerma. Herein, we evaluated the value of the IGZO detector in terms of dose efficiency in comparison to the conventional a-Si:H detector.