title: Method of duplicating film using the CR system: evaluation of detectability in a simulated nodule.
abstract: OBJECTIVE
  Since film processors used for screen-film systems have been decreasing recently, it is becoming difficult to develop duplicating film (Dup film) used conventionally. The purpose of this study was to evaluate the usefulness of the method of duplicating film using a computed radiography (CR) system.
  
  
  METHODS
  The process of duplicating film using CR is 1) to eliminate energy accumulated on the imaging plate (IP) using white light, 2) to accumulate energy on the whole surface, and 3) to place the original film in piles. 4) After an exposure of white light, duplicated films can be obtained by CR system. In order to evaluate the reproducibiliy of our system, duplicated films were read by experienced observers and receiver operating characteristic (ROC) analysis was carried out. Observers read 50 images with a simulated nodule and 50 images without a simulated nodule.
  
  
  RESULTS
  The average Az values were 0.94 for the original films, 0.91 for films duplicated using Dup film, and 0.90 for films duplicated using the CR system. When the two-tailed paired-T test was performed for each result, there were no statistically significant differences at p<0.05.
  
  
  CONCLUSIONS
  The detectability of a simulated nodule for films duplicated using the CR system did not differ from the detectability of films duplicated using Dup film. This method may be a reasonable substitute for the conventional duplication system.
authors.affiliation: Department of Medical Imaging and Information, Graduate School of Suzuka University of Medical Science, Suzuka, Mie 510-0293, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fukuyama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ando
authors.forename: Kayoko
authors.initials: K
authors.lastname: Maeda
authors.forename: Kazushi
authors.initials: K
authors.lastname: Ida
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kouichi
authors.initials: K
authors.lastname: Fukuyama
authors.forename: Takeo
authors.initials: T
authors.lastname: Hasegawa
mesh_terms: D003308:Copying Processes / Q000379:methods*; D006801:Humans; D008961:Models, Structural; D019047:Phantoms, Imaging; D012372:ROC Curve; D011856:Radiographic Image Enhancement / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*