28 May 1999 Beyond the limits of present active matrix flat-panel imagers (AMFPIs) for diagnostic radiology
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A theoretical cascaded systems analysis of the performance limits of x-ray imagers based on thin-film, active matrix flat-panel technology is presented. This analysis specifically focuses upon an examination of the functional dependence of the detective quantum efficiency on exposure. While the DQE of AMFPI systems is relatively high at the large exposure levels associated with radiographic x-ray imaging, there is a significant decline in DQE with decreasing exposure over the medium and lower end of the exposure range associated with fluoroscopic imaging. This fall-off in DQE originates from the relatively large size of the additive noise of AMFPI systems compared to their overall system gain. Therefore, strategies to diminish additive noise and increase system gain should significantly improve performance. Potential strategies for noise reduction include the use of charge compensation lines while strategies for gain enhancement include continuous photodiodes, pixel amplification structures, or higher gain converters. The effect of the implementation of such strategies is examined for a variety for hypothetical imager configurations. Through the modeling of these configurations, such enhancements are shown to hold the potential of making low frequency DQE response large and essentially independent of exposure while greatly reducing the fall-off in DQE at higher spatial frequencies.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Larry E. Antonuk, Larry E. Antonuk, Youcef El-Mohri, Youcef El-Mohri, Kyung-Wook Jee, Kyung-Wook Jee, Manat Maolinbay, Manat Maolinbay, Samer C. Nassif, Samer C. Nassif, Xiujiang Rong, Xiujiang Rong, Jeffrey H. Siewerdsen, Jeffrey H. Siewerdsen, Qihua Zhao, Qihua Zhao, Robert A. Street, Robert A. Street, } "Beyond the limits of present active matrix flat-panel imagers (AMFPIs) for diagnostic radiology", Proc. SPIE 3659, Medical Imaging 1999: Physics of Medical Imaging, (28 May 1999); doi: 10.1117/12.349530; https://doi.org/10.1117/12.349530

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