Comparison between software volumetric breast density estimates in breast tomosynthesis and digital mammography images in a large public screening cohort

Daniel Förnvik; Hannie Förnvik; Andreas Fieselmann; Kristina Lång; Hanna Sartor

doi:10.1007/s00330-018-5582-0

Comparison between software volumetric breast density estimates in breast tomosynthesis and digital mammography images in a large public screening cohort

Eur Radiol. 2019 Jan;29(1):330-336. doi: 10.1007/s00330-018-5582-0. Epub 2018 Jun 25.

Authors

Daniel Förnvik¹, Hannie Förnvik¹, Andreas Fieselmann², Kristina Lång¹, Hanna Sartor³

Affiliations

¹ Department of Medical Imaging and Physiology, Skåne University Hospital, Medical Radiology Unit, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, 205 02, Malmö, Sweden.
² Siemens Healthcare GmbH, Forchheim, Germany.
³ Department of Medical Imaging and Physiology, Skåne University Hospital, Medical Radiology Unit, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, 205 02, Malmö, Sweden. hanna.sartor@med.lu.se.

Abstract

Objectives: To compare software estimates of volumetric breast density (VBD) based on breast tomosynthesis (BT) projections to those based on digital mammography (DM) images in a large screening cohort, the Malmö Breast Tomosynthesis Screening Trial (MBTST).

Methods: DM and BT images of 9909 women (enrolled 2010-2015) were retrospectively analysed with prototype software to estimate VBD. Software calculation is based on a physics model of the image acquisition process and incorporates the effect of masking in DM based on accumulated dense tissue areas. VBD (continuously and categorically) was compared between BT [central projection (mediolateral oblique view (MLO)] and two-view DM, and with radiologists' BI-RADS density 4^th ed. scores. Agreement and correlation were investigated with weighted kappa (κ), Spearman's correlation coefficient (r), and Bland-Altman analysis.

Results: There was a high correlation (r = 0.83) between VBD in DM and BT and substantial agreement between the software breast density categories [observed agreement, 61.3% and 84.8%; κ = 0.61 and ĸ = 0.69 for four (a/b/c/d) and two (fat involuted vs. dense) density categories, respectively]. There was moderate agreement between radiologists' BI-RADS scores and software density categories in DM (ĸ = 0.55) and BT (ĸ = 0.47).

Conclusions: In a large public screening setting, we report a substantial agreement between VBD in DM and BT using software with special focus on masking effect. This automated and objective mode of measuring VBD may be of value to radiologists and women when BT is used as the primary breast cancer screening modality.

Key points: • There was a high correlation between continuous volumetric breast density in DM and BT. • There was substantial agreement between software breast density categories (four groups) in DM and BT; with clinically warranted binary software breast density categories, the agreement increased markedly. • There was moderate agreement between radiologists' BI-RADS scores and software breast density categories in DM and BT.

Keywords: Breast neoplasms; Diagnostic imaging; Digital breast tomosynthesis; Mammography; Mass screening.

Publication types

Comparative Study

MeSH terms

Breast / diagnostic imaging*
Breast Density*
Breast Neoplasms / diagnosis*
Early Detection of Cancer / methods*
Female
Humans
Mammography / methods*
Middle Aged
Prospective Studies
ROC Curve
Software*