title: Digitizing radiographic films: a simple way to evaluate indirect digital images.
abstract: 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.
authors.affiliation: Department of Stomatology, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. izrubira2000@yahoo.com.br
authors.forename: Izabel Regina Fischer
authors.initials: IR
authors.lastname: Rubia-Bullen
authors.forename: Maurício Cunha
authors.initials: MC
authors.lastname: Escarpinati
authors.forename: Homero
authors.initials: H
authors.lastname: Schiabel
authors.forename: Marcelo Andrade da Costa
authors.initials: MA
authors.lastname: Vieira
authors.forename: Cássia Maria Fischer
authors.initials: CM
authors.lastname: Rubira
authors.forename: José Roberto Pereira
authors.initials: JR
authors.lastname: Lauris