title: Comparison of breast density measured by dual energy X-ray absorptiometry with mammographic density among adult women in Hawaii.
abstract: BACKGROUND
  While use of mammography is limited, due to concerns related to radiation exposure, dual energy X-ray absorptiometry (DXA), commonly available in medical care settings, is characterized by low radiation exposure.
  
  
  METHODS
  In the current paper, we compared breast density measured by DXA with mammographic density in 101 adult women who had a screening mammogram during the last 2 years. DXA scans of both breasts were taken using a clinical DXA system calibrated to measure breast density. The total projected breast area was manually delineated on each image and percent fibroglandular volume density (%FGV), absolute fibroglandular volume, total breast area and volume were computed. After digitizing mammographic films, total breast area, dense area, and percent density (PD) were estimated using computer-assisted mammographic density assessment.
  
  
  RESULTS
  Both DXA and mammographic measures showed high correlations between left and right breasts ranging from 0.85 to 0.98 (p<0.0001). Mean %FGV was 38.8±14.3%, and mean percent density was 31.9±18.2% for craniocaudal views and 28.3±16.2% for mediolateral views. The correlation between the two measures was 0.76 for both views (p<0.0001). Associations with common risk factors showed similar patterns for DXA and mammographic densities; in particular, the inverse associations with BMI and age at menarche were evident for both methods. Multilinear regression with stepwise selection indicated an explained variance of 0.56 for %FGV alone and of 0.58 for %FGV plus number of children.
  
  
  CONCLUSIONS
  Despite some differences in methodology, the current comparison suggests that DXA may provide a low-radiation option in evaluating breast density.
authors.affiliation: Cancer Research Center of Hawaii, 1236 Lauhala St., Honolulu, HI 96813, USA. Gertraud@crch.hawaii.edu
authors.forename: Gertraud
authors.initials: G
authors.lastname: Maskarinec
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Yihe
authors.initials: Y
authors.lastname: Daida
authors.forename: Aurelie
authors.initials: A
authors.lastname: Laidevant
authors.forename: Serghei
authors.initials: S
authors.lastname: Malkov
authors.forename: John A
authors.initials: JA
authors.lastname: Shepherd
authors.forename: Rachel
authors.initials: R
authors.lastname: Novotny
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000328:Adult; D001940:Breast / Q000033:anatomy & histology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006254:Hawaii; D006801:Humans; D008327:Mammography / Q000379:methods; D008875:Middle Aged