Sensitometric properties of Agfa Dentus OrthoLux, Agfa Dentus ST8G, and Kodak Ektavision panoramic radiographic film.
OBJECTIVE
The purpose of this study was to compare the sensitometric properties of and visualization of anatomical structures with Agfa OrthoLux green-sensitive panoramic radiographic film, Agfa ST8G green sensitive panoramic radiographic film, and Kodak Ektavision green-sensitive panoramic radiographic film used in combination with an Agfa Ortho Regular 400 imaging screen, Kodak Ektavision imaging screen, and Kodak Lanex Regular imaging screen.


METHODS
The density response and resolution of panoramic radiographic film/intensifying screen combinations was evaluated by means of Hunter and Driffield curves, modulation transfer functions, and noise-equivalent number of quanta. Image clarity of selected anatomical structures was rated independently by 6 oral and maxillofacial radiologists.


RESULTS
The ISO speed for the Agfa OrthoLux panoramic radiographic film combinations was the fastest, and the ISO speed for the Kodak Ektavision green-sensitive panoramic radiographic film combinations was the slowest. The average gradient for the Agfa ST8G systems was relatively steep in comparison with those for the other film/screen combinations. The modulation transfer functions for the Kodak Ektavision film were higher than those for the other films, irrespective of the screen combination used, and those for Agfa OrthoLux film were slightly higher than those for Agfa ST8G film. The noise-equivalent number of quanta for the Agfa ST8G film/screen combinations was lower than those for the other film/screen combinations. The noise-equivalent number of quanta for the Kodak Ektavision film/screen combinations was well within the high-frequency range, whereas Agfa OrthoLux combined with either the Kodak Ektavision imaging screen or the Kodak Lanex Regular imaging screen produced a noise-equivalent number of quanta similar to those of the Kodak Ektavision film/screen combinations in the low-frequency range. Agfa OrthoLux was perceived to provide clearer images of the selected anatomical details than Agfa ST8G, and the Agfa OrthoLux/Agfa Ortho Regular 400 combination was not significantly different from the Kodak Ektavision/Kodak Lanex Regular combination in terms of perceived image quality.


CONCLUSIONS
Agfa OrthoLux is an improvement over Agfa ST8G in film speed, spatial resolution, granularity, and perceived diagnostic image quality. The Agfa OrthoLux/Agfa Ortho Regular 400 combination did not exceed the Kodak Ektavision film/Kodak Ektavision imaging screen combination in resolution, granularity, or perceived image quality.
Wakoh
M
M
Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Chiba, Japan. wakoh@tdc.ac.jp
Nishikawa
K
K
Kobayashi
N
N
Farman
A G
AG
Kuroyanagi
K
K
D000465:Algorithms; D016477:Artifacts; D003116:Color; D006801:Humans; D008334:Mandible / Q000000981:diagnostic imaging; D008443:Maxillary Sinus / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging; D015588:Observer Variation; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation; D011862:Radiography, Panoramic / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging; D013997:Time Factors; D014962:X-Ray Film / Q000145:classification*; D014963:X-Ray Intensifying Screens