At the frontiers of digital mammography: SYRMEP

The SYRMEP (SYnchrotron Radiation for MEdical Physics) collaboration is presently taking data at a beamline at the synchrotron ELETTRA in Trieste to study the performances of a digital silicon pixel imaging system for mammography. Images are obtained with a scanning technique in the energy range 15-30 keV. The readout electronics operates in a single photon counting mode with a photon rate of about 10(6)/(mm(2) s), which is still 4 times lower than the maximum rate reachable with the present beamline configuration. Two different detector layouts have been designed, the first one consisting of a single-layer silicon microstrip detector positioned edge-on with respect to the beam, and the second innovative one represented by a matrix of these detectors stacked to cover the full beam dimension (100 x 4 mm(2)). We present here the results obtained with a single-layer detector and a double-layer detector (both 5 cm wide) with mammographic phantoms and human breast tissue.