title: Intraindividual comparison of two methods of volumetric breast composition assessment.
abstract: OBJECTIVE
  To compare the results of two software-based methods, Quantra and Volpara, for volumetric breast composition assessment.
  
  
  METHODS
  Four hundred forty-five normal, bilateral, two-view, digital mammograms were included. Breast volume (BV), fibroglandular tissue volume (FTV), and percent density (PD) were measured using both methods and compared. Deming regression was performed to obtain linear equations for mapping the results of one software on the other.
  
  
  RESULTS
  The median and quartile ranges of both methods agreed well for BV but were different for FTV and PD, with Quantra showing much higher values of FTV and PD. The correlation of results obtained by both methods for BV, FTV, and PD was 0.99, 0.91, and 0.94, respectively. Intraclass correlation in the assignment of quartiles of BV, FTV, and PD was 0.96, 0.86, and 0.90, respectively. Both methods showed a similar association of FTV and PD with patient age and similar left-to-right correlation. Mapping of results onto each other using linear equations removed the systematic differences.
  
  
  CONCLUSIONS
  Although Quantra and Volpara use different models for analysis of volumetric breast composition and produce different nominal results of FTV and PD, both methods are highly correlated and show very good to excellent agreement in quartile assignment of all parameters measured. Both methods show a similar association with patient age and similar reproducibility. Both methods can be mapped onto each other using the equations suggested.
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany. Electronic address: constanze.schmachtenberg@charite.de.
authors.forename: Constanze
authors.initials: C
authors.lastname: Schmachtenberg
authors.affiliation: Department of Radiology Charité Berlin, Ärztlicher Dienst, Evangelisches Geriatriezentrum Berlin gGmbH, Berlin, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hammann-Kloss
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bick
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Engelken
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D009929:Organ Size; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012984:Software
keywords: Mammary glands; automatic data processing; breast density; human; mammography