Reproducibility of BI-RADS breast density measures among community radiologists: a prospective cohort study

Breast J. Jul-Aug 2012;18(4):326-33. doi: 10.1111/j.1524-4741.2012.01250.x. Epub 2012 May 21.


Using data from the Vermont Breast Cancer Surveillance System (VBCSS), we studied the reproducibility of Breast Imaging Reporting and Data System (BI-RADS) breast density among community radiologists interpreting mammograms in a cohort of 11,755 postmenopausal women. Radiologists interpreting two or more film-screen screening or bilateral diagnostic mammograms for the same woman within a 3- to 24-month period during 1996-2006 were eligible. We observed moderate-to-substantial overall intra-rater agreement for use of BI-RADS breast density in clinical practice, with an overall intra-radiologist percent agreement of 77.2% (95% confidence interval (CI), 74.5-79.5%), an overall simple kappa of 0.58 (95% CI, 0.55-0.61), and an overall weighted kappa of 0.70 (95% CI, 0.68-0.73). Agreement exhibited by individual radiologists varied widely, with intra-radiologist percent agreement ranging from 62.1% to 87.4% and simple kappa ranging from 0.19 to 0.69 across individual radiologists. Our findings underscore the need for additional evaluation of the BI-RADS breast density categorization system in clinical practice.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / pathology
  • Cohort Studies
  • Female
  • Humans
  • Mammography
  • Middle Aged
  • Physicians
  • Postmenopause
  • Prospective Studies
  • Radiographic Image Interpretation, Computer-Assisted
  • Radiology Information Systems / standards*
  • Reproducibility of Results
  • Vermont
  • Workforce