Digital mammographic application of a single photon counting pixel detector

We present the imaging capabilities of a system based on a single photon counting chip, bump-bounded to a Si pixel detector. The detector is 300 mum thick a matrix of 64 x 64 square pixels with a dimension side of 170 mum. The active area is about 1.2 cm(2). The photon counting chip matches the geometry of the detector so it has 4096 asynchronous read-out cells, each containing a charge preamplifier, a leading edge comparator and a pseudo-random counter. We have tested the image quality and the stability of our acquisition system imaging some phantoms used for mammografic quality checks. Our system allows to see low contrast details with a patient dose comparable with that given in mammographic examinations.