title: Comparison of dry laser printer versus paper printer in full-field digital mammography.
abstract: BACKGROUND
  Paper printers have been used to document radiological findings in some hospitals. It is critical to establish whether paper printers can achieve the same efficacy and quality as dry laser printers for full-field digital mammography (FFDM).
  
  
  OBJECTIVE
  To compare the image quality and detection rate of dry laser printers and paper printers for FFDM.
  
  
  METHODS
  Fifty-five cases (25 with single clustered microcalcifications and 30 controls) were selected by a radiologist not participating in the image review. All images were printed on film and paper by one experienced mammography technologist using the processing algorithm routinely used for our mammograms. Two radiologists evaluated hard copies from dry laser printers and paper printers for image quality and detectability of clustered microcalcifications. For the image quality comparisons, agreement between the reviewers was evaluated by means of kappa statistics. The significance of differences between both of the printers was determined using Wilcoxon's signed-rank test. The detection rate of two printing systems was evaluated using receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  From 110 scores (55 patients, two readers) per printer system, the following quality results were achieved for dry laser printer images: 70 (63.6%) were rated as good and 40 (36.4%) as moderate. By contrast, for the paper printer images, 25 scores (22.7%) were rated as good and 85 (77.3%) as moderate. Therefore, the image quality of the dry laser printer was superior to that achieved by the paper printer (P=0.00). The average area-under-the-curve (Az) values for the dry laser printer and the paper printer were 0.991 and 0.805, respectively. The difference was 0.186. Results of ROC analysis showed significant difference in observer performance between the dry laser printer and paper printer (P=0.0015).
  
  
  CONCLUSIONS
  The performance of dry laser printers is superior to that of paper printers. Paper printers should not be used in FFDM.
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liang
authors.forename: Xiangying
authors.initials: X
authors.lastname: Du
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Guo
authors.forename: Dongdong
authors.initials: D
authors.lastname: Rong
authors.forename: Ruiying
authors.initials: R
authors.lastname: Kang
authors.forename: Guangyun
authors.initials: G
authors.lastname: Mao
authors.forename: Jiabin
authors.initials: J
authors.lastname: Liu
authors.forename: Kuncheng
authors.initials: K
authors.lastname: Li
mesh_terms: D019540:Area Under Curve; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging; D016287:Computer Peripherals; D003308:Copying Processes / Q000379:methods*; D003937:Diagnosis, Differential; D004867:Equipment Design; D005260:Female; D006801:Humans; D007834:Lasers; D008327:Mammography / Q000295:instrumentation*; D015588:Observer Variation; D010209:Paper; D011327:Printing; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D011873:Radiology Information Systems; D012984:Software