Software Framework for Simulating Clusters of Microcalcifications in Digital Mammography

Abstract

Observer performance experiments for lesion detection are an accepted means of assessing the imaging performance of radiological imaging systems. Simulation methods for clusters of microcalcifications have been proposed for creating images with abnormal pathology for its use in such experiments. We report on a software tool that can generate simulated clusters of microcalcifications for different exposure parameters and different digital mammography systems. The effect of the simulation steps on microcalcification templates, (namely exposure settings, breast thickness, modulation transfer function (MTF) and pixel size) is demonstrated and validated. Results were evaluated in terms of the cluster’s peak contrast (PC) for three cases: for different exposure conditions within a given system, for different systems and for different system MTF calculation methods. As expected, with higher tube voltage and for insertion into thicker breast simulating material, the lesion contrast decreases while the position of the peak remains unchanged. When different systems are considered with the same exposure settings, the observed difference in the PCs is related to the blurring due to the different MTF and the pixel size of the systems; a shift in the peak position is also observed, due to resampling. This functional and user-friendly system could be used by other researchers for performing comparative studies of mammographic imaging systems.