title: Measuring mammographic density: comparing a fully automated volumetric assessment versus European radiologists' qualitative classification.
abstract: OBJECTIVE
  Breast Imaging-Reporting and Data System (BI-RADS) mammographic density categories are associated with considerable interobserver variability. Automated methods of measuring volumetric breast density may reduce variability and be valuable in risk and mammographic screening stratification. Our objective was to assess agreement of mammographic density by a volumetric method with the radiologists' classification.
  
  
  METHODS
  Eight thousand seven hundred and eighty-two examinations from the Malmö Breast Tomosynthesis Screening Trial were classified according to BI-RADS, 4th Edition. Volumetric breast density was assessed using automated software for 8433 examinations. Agreement between volumetric breast density and BI-RADS was descriptively analyzed. Agreement between radiologists and between categorical volumetric density and BI-RADS was calculated, rendering kappa values.
  
  
  RESULTS
  The observed agreement between BI-RADS scores of different radiologists was 80.9 % [kappa 0.77 (0.76-0.79)]. A spread of volumetric breast density for each BI-RADS category was seen. The observed agreement between categorical volumetric density and BI-RADS scores was 57.1 % [kappa 0.55 (0.53-0.56)].
  
  
  CONCLUSIONS
  There was moderate agreement between volumetric density and BI-RADS scores from European radiologists indicating that radiologists evaluate mammographic density differently than software. The automated method may be a robust and valuable tool; however, differences in interpretation between radiologists and software require further investigation.
  
  
  CONCLUSIONS
  • Agreement between qualitative and software density measurements has not been frequently studied. • There was substantial agreement between different radiologists´ qualitative density assessments. • There was moderate agreement between software and radiologists' density assessments. • Differences in interpretation between software and radiologists require further investigation.
authors.affiliation: Medical Radiology, Department of Translational Medicine, Lund University, Lund, Sweden. hanna.sartor@med.lu.se.|Department of Medical Imaging and Physiology, Skåne University Hospital, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden. hanna.sartor@med.lu.se.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sartor
authors.affiliation: Medical Radiology, Department of Translational Medicine, Lund University, Lund, Sweden.|Department of Medical Imaging and Physiology, Skåne University Hospital, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Lång
authors.affiliation: Epidemiology and Register Centre South (ERC Syd), Skåne University Hospital, Klinkgatan 22, SE-221 85, Lund, Sweden.
authors.forename: Aldana
authors.initials: A
authors.lastname: Rosso
authors.affiliation: Division of Oncology and Pathology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.|Department of Oncology, Skåne University Hospital, Getingevägen 4, SE-221 85, Lund, Sweden.
authors.forename: Signe
authors.initials: S
authors.lastname: Borgquist
authors.affiliation: Medical Radiology, Department of Translational Medicine, Lund University, Lund, Sweden.|Department of Medical Imaging and Physiology, Skåne University Hospital, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden.
authors.forename: Sophia
authors.initials: S
authors.lastname: Zackrisson
authors.affiliation: Department of Medical Radiation Physics, Department of Translational Medicine, Lund University, Lund, Sweden.
authors.forename: Pontus
authors.initials: P
authors.lastname: Timberg
mesh_terms: D000071060:Breast Density / Q000502:physiology*; D001943:Breast Neoplasms / Q000145:classification / Q000000981:diagnostic imaging / Q000473:pathology*; D005060:Europe; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D000072177:Radiologists / Q000592:standards*; D012984:Software
keywords: Breast cancer; Diagnostic imaging; Mammography; Screening; Women’ health