Image Quality Measurements in Breast Tomosynthesis

Breast tomosynthesis systems are developed by a number of manufacturers. It is desirable to have methods for image quality evaluation that can be used for quality control and minimum performance. In this study methods of measurement of three aspects of image quality (homogeneity, artifacts and detail detection on a homogeneous background) are evaluated on a prototype tomosynthesis system. The homogeneity evaluation showed that pixel value and standard deviation varied by up to respectively 6% and 30% in the tomosynthesis image. Artifacts have been quantified using an aluminium sphere of 2 mm diameter. In the plane of the object higher pixel value artefacts were visible. In all other planes artefacts were also visible. The detail detection did not fulfil the limiting values of threshold contrast for projection mammography, but image quality might have been underestimated. Homogeneity, detail detection and artifacts should be evaluated in future quality control procedures for tomosynthesis.