Digitizing radiographic films: a simple way to evaluate indirect digital images.
OBJECTIVE
This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera) using the reproducibility of pixel values attributed to the same radiographic image.


METHODS
Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility.


RESULTS
A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, p<0.00001). There was significant pixel value variability at the same digitization conditions for one scanner and the digital camera.


CONCLUSIONS
Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations.
Rubia-Bullen
Izabel Regina Fischer
IR
Department of Stomatology, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. izrubira2000@yahoo.com.br
Escarpinati
Maurício Cunha
MC
Schiabel
Homero
H
Vieira
Marcelo Andrade da Costa
MA
Rubira
Cássia Maria Fischer
CM
Lauris
José Roberto Pereira
JR