Effect of depth-dependent modulation transfer function and K-fluorescence reabsorption on the detective quantum efficiency of indirect-conversion flat-panel x-ray imaging systems using CsI

John A. Rowlands; Winston Guangda Ji; Wei Zhao

doi:10.1117/12.430931

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28 June 2001 Effect of depth-dependent modulation transfer function and K-fluorescence reabsorption on the detective quantum efficiency of indirect-conversion flat-panel x-ray imaging systems using CsI

John A. Rowlands, Winston Guangda Ji, Wei Zhao

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Proceedings Volume 4320, Medical Imaging 2001: Physics of Medical Imaging; (2001) https://doi.org/10.1117/12.430931
Event: Medical Imaging 2001, 2001, San Diego, CA, United States

Abstract

A theory of the imaging behavior of structured phosphor layers is developed based on linear analysis and Carlo model modeling and tested by comparison with experiments. The experiments include: the evaluation of Swank factor; modulation transfer function (MTF) measured as a function of spatial frequency f on CsI phosphor layers of different thicknesses and optical properties (e.g. presence or absence of reflective backing layer). These measurements on structured screens were used to establish phosphor parameters (e.g. absorption and scattering lengths). In addition, MTF(f), Wiener noise power spectra [NPS(f)] and detective quantum efficiency [DQE(f)] measurements were obtained from the literature for x-ray image intensifiers and indirect conversion flat panel detectors constructed using CsI layers. These results were compared with the theory using the previously established phosphor parameters. The effects of K-fluorescence and depth dependence of the MTF on DQE (i.e. Lubberts' effect) were investigated.

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John A. Rowlands, Winston Guangda Ji, and Wei Zhao "Effect of depth-dependent modulation transfer function and K-fluorescence reabsorption on the detective quantum efficiency of indirect-conversion flat-panel x-ray imaging systems using CsI", Proc. SPIE 4320, Medical Imaging 2001: Physics of Medical Imaging, (28 June 2001); https://doi.org/10.1117/12.430931

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