Model observer detectability as a substitute for contrast detail analysis in routine digital mammography quality control

This work investigated the substitution of CDMAM contrast detail (c-d) analysis with detectability (d’) from a non-prewhitening eye filter model observer (NPWE) for routine quality control (QC). Routinely acquired QC data for 53 systems were analyzed: 13 computed radiography (CR) and 40 integrated detector (DR) systems. For a given system, threshold gold thickness from the c-d analysis (T) was calculated from 16 images and compared against d’ calculated for 0.1 and 0.25 mm diameter discs. The d’ data were calculated from the routine 50 mm PMMA AEC image and the measured pre-sampling detector modulation transfer function (MTF). Threshold gold thickness T and d’ were plotted as function of MGD and compared.The NPWE results reflected the performance seen for T data for the majority of the systems. The correspondence between the two quality indices was examined with the Pearson correlation statistical test. This test was not applicable to the GE Essential systems because all systems are grouped together at the same working point so the result of r is about 0. For all other groups of systems the test gave good results (larger than -0.65).