Contrast perception in digitized panoramic radiographs compared with their film-based origin.
OBJECTIVE
We sought to compare the visual image quality of film-based and digitized panoramic radiographs through use of a hole-containing test wedge.


METHODS
An aluminum wedge containing 100 cells, of which 90 were given shallow holes, was exposed in the film-based Orthophos CD panoramic unit. Two radiographs subjectively exhibiting optimum contrast were selected. Films were digitized with a charge-coupled device flatbed scanner at 300 dpi. Films and digitized images were rated cellwise by 2 similar groups of 50 observers each with respect to spot perception.


RESULTS
The mean sensitivity was 0.26 +/- 0.09 for film and 0.20 +/- 0.07 for digitized images (P =.000), with a pronounced decline in the latter in regions of high background density. The average specificity was 0.93 +/- 0.07 for film versus 0.92 +/- 0.08 for digitized images (P = 0.213).


CONCLUSIONS
Film yielded a significantly higher sensitivity, but this absolute difference was actually small compared with that of the digitized images.
D015502:Absorptiometry, Photon; D000703:Analog-Digital Conversion; D003287:Contrast Media; D006801:Humans; D015588:Observer Variation; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014962:X-Ray Film
D003287:Contrast Media