title: An improved computer-assisted diagnostic scheme using wavelet transform for detecting clustered microcalcifications in digital mammograms.
abstract: OBJECTIVE
  We evaluated the potential usefulness of a computer-assisted diagnostic (CAD) scheme incorporating the wavelet transform for detecting clustered microcalcifications in mammograms.
  
  
  METHODS
  A wavelet transform technique was applied to the detection of clustered microcalcifications. We examined several wavelets to study their effectiveness in detecting subtle microcalcifications. We used a database consisting of 39 mammograms containing 41 clusters of microcalcifications. The performance of the wavelet-based CAD scheme was evaluated using free-response receiver operating characteristic analysis.
  
  
  RESULTS
  The CAD scheme with the wavelet transform was useful in detecting some of the subtle microcalcifications that were not detected by our previous scheme, which was based on the difference-image technique. When the two schemes were combined, the overall performance was improved to a sensitivity of approximately 95%, with a false-positive rate of 1.5 clusters per image.
  
  
  CONCLUSIONS
  The wavelet transform approach can improve the detection of subtle clustered microcalcifications.
authors.affiliation: Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, University of Chicago, IL 60637, USA.
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
authors.forename: K
authors.initials: K
authors.lastname: Doi
authors.forename: R M
authors.initials: RM
authors.lastname: Nishikawa
authors.forename: M L
authors.initials: ML
authors.lastname: Giger
authors.forename: R A
authors.initials: RA
authors.lastname: Schmidt
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008327:Mammography; D012372:ROC Curve; D011856:Radiographic Image Enhancement