Experimental study of Compton scattering reduction in digital mammographic imaging

In mammography, the first cause of image contrast reduction arises from the photons scattered inside the examined organ. The amount of Compton scattering strongly depends on the irradiation area and on the distance between the organ and the X-ray detector: we have experimentally evaluated how these geometrical conditions affect the scattering fraction. Our experimental setup comprises: a single photon counting device based on a Si pixel detector as X-ray sensor, a lucite cylinder to simulate the breast tissue and a lead collimator to define the irradiation area. We have evaluated the contrast and the signal to noise ratio for images acquired in different conditions.