title: Are unnecessary follow-up procedures induced by computer-aided diagnosis (CAD) in mammography? Comparison of mammographic diagnosis with and without use of CAD.
abstract: OBJECTIVE
  To evaluate the rate of unnecessary follow-up procedures recommended by radiologists using a CAD-system.
  
  
  METHODS
  185 patients (740 images) were consecutively selected from three groups (36 histologically proven cancers = group 1; 49 histologically proven benign lesions = group 2 and 100 screening cases (4 years-follow up = group 3). Mammograms were evaluated by a CAD system (Second Look, CADx, Canada). Five blinded radiologists assessed the images without/with CAD outputs. Diagnostic decisions were ranked from surely benign to surely malignant according to BIRADS classification, follow-up procedures were recommended for each observed lesion (a, screening; b, short interval follow-up examination in 6 months; c, pathologic clarification).
  
  
  RESULTS
  CAD-system detected 32/36 cancers (88.9%) (FP-rate: 1.04 massmarks and 0.27 calcmarks/image). The following values were reached by all observers without/with CAD in the mean: Sensitivity 80.6/80.0%, specificity 83.2/86.4%, PPV 53.1/58.1%, and NPV 94.6/94.7%. Observers described a similar number of additional lesions without/with the use of CAD (325/326). Whereas the number of unnecessary short-time follow up recommendations increased in all case-subgroups with CAD: 40.8/42.9% (group 1), 35.6/38.1% (group 2), 44.7/46.8% (group 3), respectively, the number of recommended biopsies decreased in all subgroups: group 1: 34.7/27.1%; group 2: 47.4/41.5%, group 3: 33.3/22.0%, respectively.
  
  
  CONCLUSIONS
  In this rather small population additional usage of CAD led to a lower rate of unnecessary biopsies. The observed decrease of recommended unnecessary biopsies due to the usage of CAD in the screening group suggests a potential financial benefit by using CAD as diagnostic aid.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University of Jena, 07740 Jena, Germany. christiane.marx@med.uni-jena.de
authors.forename: Christiane
authors.initials: C
authors.lastname: Marx
authors.forename: Ansgar
authors.initials: A
authors.lastname: Malich
authors.forename: Mirjam
authors.initials: M
authors.lastname: Facius
authors.forename: Uta
authors.initials: U
authors.lastname: Grebenstein
authors.forename: Dieter
authors.initials: D
authors.lastname: Sauner
authors.forename: Stefan O R
authors.initials: SO
authors.lastname: Pfleiderer
authors.forename: Werner A
authors.initials: WA
authors.lastname: Kaiser
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008327:Mammography; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement / Q000379:methods; D012680:Sensitivity and Specificity; D019564:Unnecessary Procedures