Initial experience of magnification tomosynthesis in depiction of suspected microcalcifications: prospective reading study of a novel reconstruction algorithm prototype

BackgroundDigital breast tomosynthesis (DBT) has several limitations with respect to microcalcification depiction. The quality of DBT images may be improved by modifying technical parameters; however, the amount of raw data and postprocessing computational time is unacceptably huge. Therefore, once detected it still seems necessary to take additional spot images to characterize microcalcifications. Additional imaging increases cumulative dose. Radiation risks and protection are raising issues nowadays.PurposeTo compare image quality of magnification tomosynthesis (t-spot) and synthetic spot magnification (s-spot) to conventional spot images in characterization of microcalcifications.Material and MethodsThis prospective single institute reading study includes 45 patients with suspected microcalcifications initially found on mammography and referred to vacuum-assisted biopsy. Conventional spot and DBT were performed. Acquired DBT data were used to reconstruct t- and s-spots. All images were reviewed by four breast radiologists in two sessions. The morphology (BI-RADS) and extent of microcalcifications were recorded. Clinical performance was evaluated using area under the receiver operating characteristic curves (AUC) for BI-RADS and Bland-Altman plots for the maximum extent of microcalcifications.ResultsAll four readers preferred t-spot to s-spot. The overall AUC for t-spot was 0.67 and for spot 0.69 with a difference lower than a non-inferiority margin (delta = 0.012, 95% confidence interval [CI] = -0.067-0.09, <i>P</i> = 0.772). Three readers underestimate the extent of microcalcifications on t-spots for both benign and malignant cases (<i>P</i> < 0.05). The discordance becomes more evident with the increasing extent of the lesion.ConclusionThe performance of conventional and reconstructed spots was similar but reader-dependent and inconclusive.