Plate scatter correction for improved performance in dual-energy imaging.
We have developed a method for correcting for the scatter produced by the computed radiography plates in single-shot dual-energy imaging. In our technique, which uses a series of four computed radiography plates (the middle two plates act as a filter), the back plate can have scatter fractions as high as 30% due to the scatter from the first three plates. We use the deconvolution method to correct for this scatter, as the scatter medium is uniform and isotropic with a constant air gap. The ratio of the modulation transfer function (MTF) of a standard computed radiography plate to that of a dual-energy plate gives us the correction factor we need to scale the Fourier transforms of our images, thus compensating for the reduced response of the system due to scatter. We also investigated the effect of having an air gap between the back dual-energy plate and the first three plates. Our measurements show that this degrades the signal-to-noise response of the back plate slightly at low spatial frequencies. We also used independent scatter fraction measurements to verify the validity of our MTF measurements. Applying the correction to a back plate image improves the fine detail contrast by approximately 30%.
Hinshaw
D A
DA
Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Dobbins
J T
JT
D000388:Air; D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008962:Models, Theoretical; D015900:Radiography, Dual-Energy Scanned Projection / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D012542:Scattering, Radiation