The purpose of this study is to investigate whether having a mammogram on differing manufacturer equipment will affect a woman’s breast density (BD) measurement. The data set comprised of 40 cases, each containing a combined image of the left craniocaudal (LCC) and left mediolateral oblique (LMLO). These images were obtained from 20 women age between 42–89 years. The images were acquired on two imaging systems (GE and Hologic) one year apart. Volumetric BD was assessed by using Volpara Density Grade (VDG) and average BD% (AvBD%). Twenty American Board of Radiology (ABR) examiners assessed the same images using the BIRADS BD scale 1-4. Statistical comparisons were performed on the means using Mann-Whitney, on correlation using Spearman’s rank coefficient of correlation and agreement using Cohen’s Kappa. The absolute median BIRADS difference between GE and Hologic was 0.225 (2.00 versus 2.00; p<0.043). The VDG measures for GE was not statistically different to Hologic (2.00 versus 2.00; p<0.877), likewise the median AvBD% for the GE and Hologic systems showed no difference (6.51 versus 6.79; p<0.935). BIRADS for GE and Hologic systems showed strong positive correlation (ρ=0.904; p<0.001), while the VDG (ρ=0.978; p<0.001) and AvBD% (ρ=0.973; p<0.001) showed very strong positive correlations. There was a substantial agreement between GE and Hologic systems for BIRADS density shown with Cohen’s Kappa (κ=0.692; p<0.001), however the systems demonstrated an almost perfect agreement for VDG (κ=0.933; p<0.001).

Date Published: 17 March 2015
PDF: 8 pages
Proc. SPIE 9416, Medical Imaging 2015: Image Perception, Observer Performance, and Technology Assessment, 94160A (17 March 2015); doi: 10.1117/12.2081725

Published in SPIE Proceedings Vol. 9416:
Medical Imaging 2015: Image Perception, Observer Performance, and Technology Assessment
Claudia R. Mello-Thoms; Matthew A. Kupinski, Editor(s)