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Signal‐to‐noise ratio considerations in radiographic imaging
Author(s) -
Chakraborty D. P.,
Barnes G. T.
Publication year - 1983
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.595310
Subject(s) - aperture (computer memory) , signal to noise ratio (imaging) , optics , computed radiography , radiography , noise (video) , signal (programming language) , coded aperture , medical imaging , physics , range (aeronautics) , mathematics , computer science , acoustics , image quality , computer vision , artificial intelligence , materials science , image (mathematics) , detector , composite material , nuclear physics , programming language
The methodology employed to calculate radiographic signal‐to‐noise ratio (SNR) for the commonly used disk‐shaped test object is reviewed. Although the “matched” aperture yields the maximum SNR, its shape is difficult to achieve experimentally. On the other hand, a circular aperture having the same size as the object is much simpler to realize. We have performed a numerical analysis of the SNRs obtained with matched and circular apertures for two screen/film systems (a mammographic and a general purpose combination) for a range of test‐object sizes. We find that for object sizes greater than 0.5 mm in diameter, there is a less than 4% difference between the SNRs obtained with the two apertures. The shapes of some of the matched apertures are also presented. We conclude that the SNR determined with the circular aperture is a simpler and more useful determinant of system performance for the screen/film combinations studied.