Image Quality and Radiation Dose in Propagation Based Phase Contrast Mammography with a Microfocus X-ray Tube: A Phantom Study

摘要

Digital mammography has limitations in sensitivity, in particular for patients with a dense breast. Phase contrast techniques (phase contrast mammography, PCM) might increase the tissue contrast for breast imaging. Propagation based PCM with a dedicated 0.1-mm-focal spot size mammography unit was investigated in past years, showing higher image quality in magnification PCM than in absorption based DM. In this work the authors investigated, using breast phantoms, the dependence of image quality on increasing mean glandular dose with a 0.007-mm-focal spot size W-anode microfocus X-ray tube. They compared PCM imaging (magnification M ≌ 2) to absorption based contact imaging (M ≌ 1) and then to phase retrieval for phase imaging, at low (40 kV) as well as high (80 kV) beam energy. Phase imaging shows higher image contrast for glandular masses and microcalcifications with MGD similar to one-view mammography. The phase contrast power spectrum assumes higher values than for absorption imaging. Possibility of dose reduction was suggested by the adoption of phase retrieval PCM.