Premium
The relationship between pixel value and beam quality in photostimulable phosphor imaging
Author(s) -
Tucker Douglas M.,
Rezentes Paul S.
Publication year - 1997
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 - 10.1118/1.598007
Subject(s) - pixel , image quality , optics , beam (structure) , materials science , computed radiography , phosphor , digital radiography , range (aeronautics) , image sensor , nuclear medicine , radiography , physics , computer science , medicine , artificial intelligence , optoelectronics , image (mathematics) , composite material , nuclear physics
Direct digital capture systems are relatively new in diagnostic imaging. Full utilization of these devices requires a thorough understanding of the image formation process. The conversion of x‐ray photon energy to a digital pixel value in a commercially available photostimulable phosphor (PSP) imaging system is investigated in this paper. Pixel values measured at 16 different combinations of 4 x‐ray beam peak voltages (60, 80, 100, and 120 kVp) and 4 beam qualities are reported. At 60 and 80 kVp exposures were made at2.58 × 10− 7 C / kg (1 mR); at 100 and 120 kVp exposures were made at5.16 × 10− 7 C / kg (2 mR). Analysis of variance was used to determine the statistical significance of the relationship between pixel value and beam quality for a given kVp and exposure. A computer model accounting for x‐ray spectral effects that accurately predicts pixel value is presented. Calculated pixel values agree within 5.0% of measured values over the range of beam energies, exposures, and qualities.