25 April 2000 Optimization of MTF and DQE in magnification radiography: a theoretical analysis
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MTFs and focal spot intensity profiles were modeled as Gaussian functions. The overall resolution limits of the MTF were derived as a function of the magnification factor, detector resolution limit and focal spot size. The MTF and NPS for a small field digital mammography system was measured and used to compute NEQ for various magnification factors. Computation of DQE is discussed. Images of simulated microcalcification cluster were acquired and used to demonstrate the improvement of low contrast detectability in magnification imaging. It was shown that MTF improves with magnification when the detector MTF is low. The improvement decreases as the detector MTF increases. It was observed that at low to medium frequencies, the MTF improvement would be limited by the focal spot blurring effect while at high frequencies, the MTF improves with all magnification factors. The NEQ was found to improve with magnification factor. The microcalcification detectability was also found to improve as the magnification is increased.
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Chris C. Shaw, Chris C. Shaw, Xinming Liu, Xinming Liu, Michael R. Lemacks, Michael R. Lemacks, John X. Rong, John X. Rong, Gary J. Whitman, Gary J. Whitman, "Optimization of MTF and DQE in magnification radiography: a theoretical analysis", Proc. SPIE 3977, Medical Imaging 2000: Physics of Medical Imaging, (25 April 2000); doi: 10.1117/12.384522; https://doi.org/10.1117/12.384522

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