Evaluating the effect of dose on reconstructed image quality in digital tomosynthesis

Breast tomosynthesis has the potential to improve lesion visibility and localization compared to conventional mammography. To be clinically useful, tomosynthesis must be able to achieve high image quality at acceptable radiation doses. Tomosynthesis data sets of simple low-contrast phantoms were acquired at varying dose levels. Image quality in the reconstructed volumes was analyzed by evaluating the voxel-to-voxel signal difference to noise ratio between a simulated lesion and the surrounding "tissue". Preliminary results indicate that image quality of small lesions is limited by scatter and reconstruction artifacts. In uniform backgrounds image quality appears to be quantum-noise limited, while in more complex backgrounds the structural noise tends to dominate.