Applicability of virtual breast phantoms for detectability studies in synthetic mammography

The required realism of virtual breast phantoms is likely to depend on the imaging modality and the task. This work investigates the extent to which the VICTRE breast models are suitable for the evaluation of synthetic mammography (SM) in terms of statistical texture properties and microcalcification detection performance. First, a power spectrum analysis was performed on digital breast tomosynthesis (DBT) and SM images of patients and virtual phantoms, including all four breast density categories. The fitted power law exponent 𝛽 was used to characterize breast texture. Next, calcification clusters were simulated in patient and phantom backgrounds acquired with three different DBT dose distributions applied over the projections. A human observer detectability study was performed. The power spectrum analysis showed slightly lower power law exponents for patients compared to virtual breast phantoms. The trend of 𝛽 across different density categories is similar for patient and phantom SM images. Additionally, trends in the detectability study with virtual phantoms were similar to those in the patient study, however, the absolute performance values and level of significance between the different dose distributions were not identical. Nevertheless, this suggests that the VICTRE breast phantoms are potentially valuable replacements for patients in system optimization studies for microcalcification detection in SM and DBT.