title: Mass detection in digitized mammograms using two independent computer-assisted diagnosis schemes.
abstract: OBJECTIVE
  Using two independent computer-assisted diagnosis (CAD) schemes, we investigated the potential to improve the sensitivity of mass detection by applying a logical "or" operation and to improve the specificity using a logical "and" operation.
  
  
  METHODS
  Two independent mass detectors, one with Gaussian bandpass filtering and multilayer topographic feature analysis and the other with a five-stage search for a single suspicious region, were applied to a large image database that included 428 digitized mammograms with 220 verified masses. The performance of the two schemes and a combination of them in the form of either logical "or" or logical "and" operations were compared.
  
  
  RESULTS
  In this preliminary study, a multilayer topographic feature analysis CAD scheme (CAD-1) achieved a sensitivity of 96% and had a false-positive detection rate of 0.79 per image. A five-stage search method scheme (CAD-2) achieved a sensitivity of 94% and had a false-positive detection rate of 1.69 per image. With an "or" operation, the combined results yielded 100% sensitivity with a false-positive detection rate of 2.07 per image. A logical "and" operation produced a reduction of the false-positive detection rate to 0.4 per image, but sensitivity also decreased to 90%.
  
  
  CONCLUSIONS
  Similar to an independent double-reading approach and depending upon the relevant clinical question, sensitivity or specificity can be improved by combining the results of several independent CAD schemes.
authors.affiliation: Department of Radiology, University of Pittsburgh, PA 15261-0001, USA.
authors.forename: B
authors.initials: B
authors.lastname: Zheng
authors.forename: Y H
authors.initials: YH
authors.lastname: Chang
authors.forename: D
authors.initials: D
authors.lastname: Gur
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003936:Diagnosis, Computer-Assisted; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity