Determination of system geometrical parameters and consistency between scans for contrast-enhanced digital breast tomosynthesis

Abstract

Digital breast tomosynthesis (DBT) requires precise knowledge of acquisition geometry for accurate image reconstruction. Further, image subtraction techniques employed in dual-energy contrast-enhanced tomosynthesis require that scans be performed under nearly identical geometrical conditions. A geometrical calibration algorithm is developed to investigate system geometry and geometrical consistency of image acquisition between consecutive digital breast tomosynthesis scans, according to requirements for dual-energy contrast-enhanced tomosynthesis. Investigation of geometrical accuracy and consistency on a prototype DBT unit reveals accurate angular measurement, but potentially clinically significant differences in acquisition angles between scans. Further, a slight gantry wobble is observed, suggesting the need for incorporation of gantry wobble into image reconstruction, or improvements to system hardware. © 2012 Springer-Verlag Berlin Heidelberg.