[Image quality and detection performance of a direct digital radiography system].
The physical characteristics of a direct amorphous Selenium (a-Se) digital fluoroscopy and radiography system were investigated. Pre-sampled modulation transfer functions (MTF) were measured using a slit method. Noise power spectra were determined for different input exposures by fast Fourier transform of uniformly exposed samples. The MTFs of direct digital radiography systems showed significantly higher values than those of indirect digital radiography and screen-film systems. The direct digital radiography systems showed higher noise levels compared with those of indirect systems under roughly the same exposure conditions. Contrast-detail analysis was performed to compare detection by direct digital radiography systems with that of the screen-film (FUJI HG-M2/UR2) systems. The average contrast-detail curves of digital and film images were obtained from the results of observation. Image quality figures (IQF) were also calculated from the individual observer performance tests. The results indicated that digital contrast-detail curves and IQF are, on average, are equal those of the screen-film system.
Ideguchi
Tadamitsu
T
Department of Radiology, Clinical Research Institute, National Hospital Organization Kyushu Medical Center.
Matsuda
Katsuhiko
K
Himuro
Kazuhiko
K
Kuwahara
Rie
R
Miyazaki
Hidetsune
H
Hazeyama
Hiroyuki
H
Kumazawa
Seiji
S
Kawaji
Yasuyuki
Y
Yoshida
Akira
A
Matsumoto
Masao
M
Higashida
Yoshiharu
Y
D005583:Fourier Analysis; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods; D014963:X-Ray Intensifying Screens