title: Association between subjective evaluation and physical parameters for radiographic images optimization.
abstract: OBJECTIVE
  The purpose of this study was to develop a methodology to optimize computed radiographic techniques to image the skull, chest, and pelvis of a standard patient.
  
  
  METHODS
  Optimization was performed by varying exposure levels with different tube voltages to generate images of an anthropomorphic phantom. Image quality was evaluated using visual grading analysis and measuring objective parameters such as the effective detective quantum efficiency and the contrast-to-noise ratio. Objective and subjective evaluations were compared to obtain an optimized technique for each anatomic region.
  
  
  RESULTS
  Gold standard techniques provided a significant reduction in X-ray doses compared to the techniques used in our radiology service, without compromising diagnostic accuracy. They were chosen as follows 102 kVp/1.6 mAs for skull; 81 kVp/4.5 mAs for pelvis and 90 kVp/3.2 mAs for chest.
  
  
  CONCLUSIONS
  There is a range of acceptable techniques that produce adequate images for diagnosis in computed radiography systems. This aspect allows the optimization process to be focused on the patient dose without compromising diagnostic capabilities. This process should be performed through association of quantitative and qualitative parameters, such as effective detective quantum efficiency, contrast-to-noise ratio, and visual grading analysis.
authors.affiliation: Department of Physics and Biophysics, Biosciences Institute of Botucatu, São Paulo State University, Distrito de Rubião Junior S/N, Botucatu, São Paulo, 18618-000, Brazil. Electronic address: allan@ibb.unesp.br.
authors.forename: A F F
authors.initials: AF
authors.lastname: Alves
authors.affiliation: Department of Physics and Biophysics, Biosciences Institute of Botucatu, São Paulo State University, Distrito de Rubião Junior S/N, Botucatu, São Paulo, 18618-000, Brazil. Electronic address: matheus@ibb.unesp.br.
authors.forename: M
authors.initials: M
authors.lastname: Alvarez
authors.affiliation: Department of Tropical Diseases and Diagnostic Imaging, Botucatu Medical School São Paulo State University, Distrito de Rubião Junior S/N, Botucatu, São Paulo, 18618-000, Brazil. Electronic address: sribeiro@fmb.unesp.br.
authors.forename: S M
authors.initials: SM
authors.lastname: Ribeiro
authors.affiliation: Brazilian Center of Physics Research - CBPF-MCT, Dr. Xavier Sigaud, 150, Rio de Janeiro, 22290-180, Brazil. Electronic address: sbd@cbpf.br.
authors.forename: S B
authors.initials: SB
authors.lastname: Duarte
authors.affiliation: Department of Physics and Biophysics, Biosciences Institute of Botucatu, São Paulo State University, Distrito de Rubião Junior S/N, Botucatu, São Paulo, 18618-000, Brazil. Electronic address: jmiranda@ibb.unesp.br.
authors.forename: J R A
authors.initials: JR
authors.lastname: Miranda
authors.affiliation: Department of Tropical Diseases and Diagnostic Imaging, Botucatu Medical School São Paulo State University, Distrito de Rubião Junior S/N, Botucatu, São Paulo, 18618-000, Brazil. Electronic address: drpina@fmb.unesp.br.
authors.forename: D R
authors.initials: DR
authors.lastname: Pina
mesh_terms: D000886:Anthropometry; D003287:Contrast Media / Q000737:chemistry; D006801:Humans; D008297:Male; D010388:Pelvis / Q000528:radiation effects; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods* / Q000592:standards; D011859:Radiography / Q000379:methods* / Q000592:standards*; D015203:Reproducibility of Results; D012886:Skull / Q000528:radiation effects; D013909:Thorax / Q000528:radiation effects; D014965:X-Rays
chemical_list: D003287:Contrast Media
keywords: Computed radiography; Dose; Image quality; Radiology