Detection of microcalcification clusters in 2D-mammography and digital breast tomosynthesis and the relation to the standard method of measuring image quality

Abstract

The aim of this study was to compare the detection of microcalcification clusters by human observers in breast images using 2D-mammography and narrow (15°/15 projections) and wide (50°/25 projections) angle digital breast tomosynthesis (DBT). Furthermore, the relation between the standard European method of measuring mammographic image quality using the CDMAM phantom and the calcification detection in 2D mammography and DBT was investigated. Images of 6 cm thick simulated compressed breasts, were produced with and without inserted microcalcification clusters using a set of image modelling tools, which were developed to represent clinical imaging by mammography and DBT. The simulated microcalcification clusters had a range of microcalcification diameters (100 μm-500 μm). Commercially available software was used for image processing and image reconstruction. The images were then used in a series of 4-alternative forced choice human observer experiments conducted for signal detection with the microcalcification clusters as targets. For each of the three imaging modalities the threshold diameter required for microcalcification detection was determined. Results showed that 2D-mammography has a lower threshold diameter for microcalcification detection than both DBT imaging modalities and that narrow angle DBT has a lower threshold diameter than wide angle DBT. Additionally, it was shown that the CDMAM-determined threshold gold thickness is a good predictor of microcalcification detection.