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Determination of the two‐dimensional detective quantum efficiency of a computed radiography system
Author(s) -
Båth Magnus,
Håkansson Markus,
Månsson Lars Gunnar
Publication year - 2003
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 - 10.1118/1.1625442
Subject(s) - detective quantum efficiency , optical transfer function , optics , computed radiography , digital radiography , aperture (computer memory) , spatial frequency , detector , nyquist frequency , physics , radiography , image quality , mathematics , computer science , image (mathematics) , computer vision , acoustics , filter (signal processing) , nuclear physics
Based on a recently described method for determining the two‐dimensional presampling modulation transfer function (MTF), the aperture mask method, a method for determining the two‐dimensional detective quantum efficiency (DQE) of a digital radiographic system was developed. The method was applied to a new computed radiography (CR) system and comparisons with one‐dimensional determinations of the presampling MTF and the DQE were performed. The aperture mask method was shown to agree with the conventional tilted slit method for determining the presampling MTF along the axes. For the particular CR system studied, the mean of one‐dimensional determinations of the DQE in orthogonal directions led to a representative measure of the average DQE behavior of the system up to the Nyquist frequency along the axes, but a deviation was observed above this frequency. In conclusion, the method developed for determining the two‐dimensional DQE can be used to determine the imaging properties of a digital radiographic detector system over almost the entire frequency domain, the exception being the lowest frequencies ( ⩽ 0.1 mm − 1) at which the validity and the reliability of the method are low.