Comparison of SNDR, NPWE model and human observer results for spherical densities and microcalcifications in real patient backgrounds for 2D digital mammography and breast tomosynthesis

Abstract

The development of objective detection performance measures is of great value for both optimization purposes and inter-comparison of different mammographic (2D) or digital breast tomosynthesis (DBT) systems. They would be valuable as an alternative for human observer studies. In this study, we have calculated contrast (C), signal-difference-to-noise ratio (SDNR) and a NPWE model observer (d') for spherical densities and microcalcifications in patient 2D and DBT images. Contrast was higher in 2D compared to DBT reconstructions. In contrary, SDNR values were higher in DBT for the spheres and were comparable between 2D and DBT for the microcalcifications. A comparison between d' and SDNR showed a strong correlation between these two measures for both spheres and microcalcifications in 2D and DBT. Only weak and moderate correlations were found for SDNR and d' versus human confidence scores, indicating that there is room for improvement for the NPWE model observer as a theoretical predictor of human detection performance. © 2014 Springer International Publishing.