title: Mammography and subsequent whole-breast sonography of nonpalpable breast cancers: the importance of radiologic breast density.
abstract: OBJECTIVE
  Our purpose was to determine the contribution of mammography followed by sonography for the detection of nonpalpable breast cancers in Breast Imaging Reporting and Data System (BI-RADS) density grades 1-4 breasts, in grades 1 and 2 breasts, and in grades 3 and 4 breasts.
  
  
  METHODS
  The results of physical, mammographic, and sonographic examinations performed in 4236 patients were reviewed to determine the sensitivities of mammography and sonography for the detection of nonpalpable breast cancers and to calculate the relative risk for detecting nonpalpable breast cancers using sonography in comparison with mammography in density grades 1-4, grades 1 and 2, and grades 3 and 4 breasts. Sonography was performed after mammographic interpretation.
  
  
  RESULTS
  Sensitivities of mammography and subsequent sonography for the detection of nonpalpable breast cancers were 69% and 88% in grades 1-4, 80% and 88% in grades 1 and 2, and 56% and 88% in grades 3 and 4 breasts, respectively. The relative risk for detecting nonpalpable breast cancers using sonography was statistically significantly greater than that for detecting nonpalpable breast cancers using mammography in grades 1-4 (relative risk, 1.29; p = 0.024) and in grades 3 and 4 (relative risk, 1.57; p = 0.013) but not in grades 1 and 2 (relative risk, 1.1; p = 0.445) breasts.
  
  
  CONCLUSIONS
  Sonography is a useful adjunct after mammography for the detection of nonpalpable breast cancer, particularly in the dense breast.
authors.affiliation: Department of Radiology, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Ave. Hippocrate 10, B-1200 Brussels, Belgium.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Leconte
authors.forename: Chantal
authors.initials: C
authors.lastname: Feger
authors.forename: Christine
authors.initials: C
authors.lastname: Galant
authors.forename: Martine
authors.initials: M
authors.lastname: Berlière
authors.forename: Bruno Vande
authors.initials: BV
authors.lastname: Berg
authors.forename: William
authors.initials: W
authors.lastname: D'Hoore
authors.forename: Baudouin
authors.initials: B
authors.lastname: Maldague
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D010173:Palpation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016217:Ultrasonography, Mammary