title: Lumbar spine radiography: digital flat-panel detector versus screen-film and storage-phosphor systems in monkeys as a pediatric model.
abstract: OBJECTIVE
  To assess image quality and exposure dose requirements of a flat-panel detector system versus screen-film and storage-phosphor systems for radiographic depiction of the lumbar spine in Cynomolgus monkeys as a pediatric model.
  
  
  METHODS
  Twenty Cynomolgus monkeys underwent anteroposterior radiography of the lumbar spine. The size and weight of these monkeys are comparable to those of infants 3-4 months of age. Images were acquired with speed class 400 screen-film, flat-panel, and storage-phosphor systems with identical exposure dose. All other conditions were matched exactly. Additional images were acquired with the flat-panel and storage-phosphor systems at exposure doses equivalent to speed classes 800 and 1600. All images were obtained at 66 kVp without antiscatter grid. Images were assessed independently by three radiologists for visibility of 60 anatomic structures by using a five-point confidence scale. Scores were calculated for the seven combinations of imaging mode and exposure dose and were compared by using the Friedman test.
  
  
  RESULTS
  Scores were 1.70 (speed class 400), 1.97 (speed class 800), and 2.27 (speed class 1600) for the flat-panel system; 2.50 (speed class 400) for the screen-film system; and 2.58 (speed class 400), 2.77 (speed class 800), and 3.13 (speed class 1600) for the storage-phosphor system. Scores for the flat-panel system at speed classes 400 and 800 were significantly lower (indicating better visibility) than those of the screen-film and storage-phosphor systems (P <.05).
  
  
  CONCLUSIONS
  The flat-panel system is superior to screen-film and storage-phosphor systems in lumbar spine radiography in monkeys. With the flat-panel system, exposure dose can be reduced by 75% without loss in image quality.
authors.affiliation: Department of Clinical Radiology, University of Münster, Germany. karl.ludwig@ok.uni-heidelberg.de
authors.forename: Karl
authors.initials: K
authors.lastname: Ludwig
authors.forename: Kathrin
authors.initials: K
authors.lastname: Ahlers
authors.forename: Dag
authors.initials: D
authors.lastname: Wormanns
authors.forename: Michael
authors.initials: M
authors.lastname: Freund
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Bernhardt
authors.forename: Stefan
authors.initials: S
authors.lastname: Diederich
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007223:Infant; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008252:Macaca fascicularis; D023421:Models, Animal; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D014963:X-Ray Intensifying Screens