title: Image quality of digital direct flat-panel mammography versus an analog screen-film technique using a low-contrast phantom.
abstract: OBJECTIVE
  The objective of our study was to compare the detectability and distinguishability of simulated soft-tissue opacities of 50 variants of an anthropomorphic breast phantom in mammograms acquired with a digital direct flat-panel detector versus an analog system; we also compared the image settings "analog film," "digital film," and "digital monitor."
  
  
  METHODS
  The studies were performed on digital (Lorad Selenia) and analog (Mammomat 3) mammography systems. Four hundred fifty silicone cubes devised with different randomly distributed columns, holes, or both columns and holes (diameter, 3-7 mm; height, 0.5-4.0 mm) were used as test bodies. One experimental series was performed with a silicone scatter body and one with a silicone and an anthropomorphic ground-meat scatter body. All x-rays were obtained at identical settings and exposures. Four radiologists rated the films and monitor-displayed images independently of each other in randomized order on a standardized electronic questionnaire.
  
  
  RESULTS
  The digital monitor technique generally scored better than digital film viewing and analog readings. The McNemar test for multiple paired comparisons mostly yielded a p value of < 0.0005. The smallest volume category counted as the most valid test scenario for all raters, where the percentage of correct positive findings ranged between 30% and 58% (analog technique), 43% and 68% (digital film viewing), and 55% and 66% (monitor viewing). The corresponding accuracy rates were 77-93%, 75-95%, and 81-85%, respectively, with kappa values of 0.2-0.5 (analog) and 0.3-0.6 (digital) for comparing the gold standard with raters' evaluations.
  
  
  CONCLUSIONS
  Digital flat-panel mammography is superior to the analog screen-film method for the detection of simulated opacities.
authors: Department of Radiology, University of Cologne Medical School, Kerpenerstrasse 62, Cologne NRW 50924, Germany. barbara.krug@uk-koeln.de
authors: Kathrin Barbara
authors: KB
authors: Krug
authors: Hartmut
authors: H
authors: Stützer
authors: René
authors: R
authors: Schröder
authors: Julia
authors: J
authors: Boecker
authors: Jörg
authors: J
authors: Poggenborg
authors: Klaus
authors: K
authors: Lackner
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014963:X-Ray Intensifying Screens