Initial evaluation of a full breast digital system

Full-field digital mammography systems have been developed for overcoming the limitations of the screen-film mammography. This work is focused on the system from GE Medical Systems (Senographe 2000) which has been recently installed in our institution. The imager consists of a thin Ics:Tl scintillator which is in narrow contact with an array of amorphous silicon detectors mounted in a single panel. The flat-panel detector is integrated in a x-ray system with a high-frequency generator Senographe DM and dual track anode of Mo and Rh with Mo and Rh filtration. The aim of this work is to analyse the defaults exposure factors set at the installation of the x-ray unit. The image quality has been evaluated by using one of the two phantoms recommended in the ACR Accreditation Program. Phantom images were obtained at each of the three available imaging modes: contrast (CNT), standard (STD) and DOSE. While maintaining the defaults of kilovoltage and anode/filter combination, phantom images were obtained at lower dose vales. The contrast noise ratio (CNR) was calculated for each of the low contrast objects (masses) of the phantom images and the detail visibility was also evaluated. The results obtained for both parameters reveal that similar image quality can be obtained with significant reductions of the average glandular dose. (author)