title: Computer-aided detection in mammography: an assessment of performance on current and prior images.
abstract: OBJECTIVE
  The authors assessed and compared the performance of a computer-aided detection (CAD) scheme for the detection of masses and microcalcification clusters on a set of images collected from two consecutive ("current" and "prior") mammographic examinations.
  
  
  METHODS
  A previously developed CAD scheme was used to assess two consecutive screening mammograms from 200 cases in which the current mammogram showed a mass or cluster of microcalcifications that resulted in breast biopsy. The latest prior examinations had been initially interpreted as negative or definitely benign findings (Breast Imaging Reporting and Data System rating, 1 or 2). The study involved images of 400 examinations acquired in 200 patients. Radiologists identified 172 masses and 128 clusters of microcalcifications on the current images. The performance of the CAD scheme was analyzed and compared for the current and latest prior images.
  
  
  RESULTS
  There were significant differences (P < .01) between current and prior images in many feature values. The performance of the CAD scheme was significantly lower for prior than for current images (P < .01). At 0.5 and 0.2 false-positive mass and cluster cues per image, the scheme detected 78 malignant masses (78%) and 63 malignant clusters (80%) on current images. Only 42% of malignant cases were detected on prior images, including 40 masses (40%) and 36 microcalcification clusters (46%).
  
  
  CONCLUSIONS
  CAD schemes can detect a substantial fraction of masses and microcalcification clusters depicted on prior images. To improve performance with prior images, the scheme may have to be adaptively reoptimized with increasingly more subtle abnormalities.
authors.affiliation: Department of Radiology, University of Pittsburgh and Magee-Womens Hospital, PA 15213, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Ratan
authors.initials: R
authors.lastname: Shah
authors.forename: Luisa
authors.initials: L
authors.lastname: Wallace
authors.forename: Christiane
authors.initials: C
authors.lastname: Hakim
authors.forename: Marie A
authors.initials: MA
authors.lastname: Ganott
authors.forename: David
authors.initials: D
authors.lastname: Gur
mesh_terms: D001941:Breast Diseases / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted