Relationship between radiation dose and image quality in digital breast tomosynthesis

This phantom-based study aimed to examine radiation dose from digital breast tomosynthesis (DBT) and digital mammography (DM) and to assess the potential for dose reductions for each modality. Images were acquired at 10-60 mm thicknesses and four dose levels and mean glandular dose was determined using a solid-state dosemeter. Eleven readers assessed image quality and compared simulated lesions with those on a reference image, and the data produced was analysed with the Friedman and Wilcoxon signed-rank tests. For a phantom thickness of 50 mm (typical breast thickness), DBT dose was 13 % higher than DM, but this differential is highly dependent on thickness. Visibility of masses was equal to a reference image (produced at 100 % dose) when dose was reduced by 75 and 50 % for DBT and DM. For microcalcifications, visibility was comparable with the reference image for both modalities at 50 % dose. This study highlighted the potential for reducing dose with DBT. (authors)