Speaker
Mr
Erik Vallazza
(INFN Triest)
Description
During 2006 the SYRMEP (Synchrotron Radiation for Medical Physics)
collaboration performed worldwide unique clinical mammographic
examinations using X-rays generated by one of the bending magnets at the
synchrotron radiation facility Elettra (Trieste, Italy). While these
examinations have been performed with traditional screen-film systems,
recently a major effort has been pursued in order to exploit the so-called
phase contrast imaging with a monochromatic laminar high-rate X-ray beam
in combination with a suitable digital detector. The INFN MATISSE project
(Mammographic and Tomographic Imaging with Silicon detectors and
Synchrotron radiation at Elettra) and the Paul Scherrer Institut have
developed a digital detector based on a microstrip silicon sensor (50 μm
pitch) coupled to the Mythen-II high-rate photon counting ASIC. This
detector, which uses the edge-on technique to improve the detection
efficiency, features a total of 2368 readout channels covering a beam width
of about 12 cm. The system, which can be modeled as a paralyzing single
photon counter, enables X-ray imaging at the quantum limit for photon
fluence as high as 70 MHz/mm 2. This contribution presents the
characterization of the device in terms of its detective quantum efficiency
(DQE ) and the images of standard and lowcontrast phantoms recorded in
standard absorption geometry and in the phase contrast imaging modality.
Author
Mr
Erik Vallazza
(INFN Triest)
