In this contribution, we therefore present an approach for reducing such metal artefacts by means of a three-pass reconstruction method. The method analyzes the reconstructed tomosynthesis volume for metal contributions. It eventually determines corresponding pixels in the projection data, and decomposes the projections accordingly into metal and nonmetal projections. After each projection set is reconstructed independently, the final, enhanced tomosynthesis volume is obtained by a non-linear blending operation.
The proposed approach was evaluated on a set of eight clinical cases. Each breast contained a metal clip, which is typically left as marker after biopsy. The proposed method achieved to retain the appearance of the metal object in the focal and its adjacent slices. At the same time complete removal of streak artefacts in all distant slices was achieved. Efficacy of the method in presence of larger objects was demonstrated in phantom studies, where visibility of microcalcifications was completely restored.