title: Computed radiography versus screen-film radiography: detection of pulmonary edema in a rabbit model that simulates neonatal pulmonary infiltrates.
abstract: OBJECTIVE
  To determine if computed radiography is equivalent to screen-film radiography in depicting pulmonary edema and to determine if radiation exposure can be reduced with computed radiography while maintaining equivalent diagnostic accuracy for pulmonary edema.
  
  
  METHODS
  Oleic acid was intravenously injected into three rabbits at each of four doses: 0, 0.02, 0.04, and 0.06 mL/kg. Two hours later, chest computed radiographs and screen-film radiographs were obtained at 60 kVp and 1.1 mAs. Additional computed radiographs were obtained after reducing milliampere seconds or by reducing milliampere seconds and increasing the kilovolt peak, which reduced bone marrow exposure by up to 20%. The presence of pulmonary opacities, "truth," was established by the wet-dry weight ratio and by chest computed tomography (CT). The radiographs were masked and randomized. Four observers rated the images for the presence of parenchymal opacities with a dichotomous score and judged the quality of the radiographs on a scale from 1 (worst) to 6 (best). Cochran Q tests and McNemar tests were used to analyze the differences in paired comparisons. Image quality was evaluated with logistic regression analysis.
  
  
  RESULTS
  There was no significant difference between truth and observer ability to detect opacity for either modality or for any exposure (P > .05). There was no significant difference between computed radiography and screen-film radiography for image quality (P > .05).
  
  
  CONCLUSIONS
  Computed radiography is equivalent to screen-film radiography in the detection of pulmonary edema. Radiation exposure reduction of 20% can be achieved without affecting pulmonary edema detection or image quality.
authors.affiliation: Mallinckrodt Institute of Technology, St Louis Children's Hospital, Washington University School of Medicine, MO 63110, USA. don@mirlink.wustl.edu
authors.forename: S
authors.initials: S
authors.lastname: Don
authors.forename: C F
authors.initials: CF
authors.lastname: Hildebolt
authors.forename: T L
authors.initials: TL
authors.lastname: Sharp
authors.forename: G D
authors.initials: GD
authors.lastname: Shackelford
authors.forename: D M
authors.initials: DM
authors.lastname: Lau
authors.forename: T E
authors.initials: TE
authors.lastname: Herman
authors.forename: W H
authors.initials: WH
authors.lastname: McAlister
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D015588:Observer Variation; D011654:Pulmonary Edema / Q000000981:diagnostic imaging*; D011817:Rabbits; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D014963:X-Ray Intensifying Screens / Q000706:statistics & numerical data