Improvements in the field of radiological imaging at the SYRMEP beamline

Abstract

One major goal of modern radiology is the improvement of image quality and subsequently the development of sophisticated radiographic methods which are capable of detecting low contrast and small size details in organic samples in particular in mammography where the requirements on contrast resolution and spatial resolution are extremely high. Significant improvements in image quality have been achieved by the SYRMEP (SYnchrotron Radiation for MEdical Physics) collaboration which has designed and built a beamline devoted to medical physics at the synchrotron radiation facility ELETTRA in Trieste (Italy). The detection system developed for digital mammography consists of a silicon pixel detector with a pixel size of 200 X 300 micrometers <SUP>2</SUP> used in the `edge on' configuration in order to achieve a high conversion efficiency. The detector is equipped with a low noise VLSI amplifier chain; at present. Recently, a multilayer detector prototype has been implemented, consisting of a stack of three single silicon strip layers. This set-up provides a larger sensitive area and subsequently a reduction of the exposure time. Digital images of mammographic phantoms and of in vitro full breast tissue samples show a higher contrast resolution and lower absorbed dose when compared to conventional mammographic images. Besides, further promising studies have been initiated developing novel imaging methods based on the phase effects evidenced by the high degree of coherence of the SR source. At the SYRMEP beamline several experiments have been carried out in order to exploit the potentials of two different techniques, Phase Contrast and Diffraction Enhanced Imaging, respectively. Images showing better detail visibility and enhanced contrast were produced with dose lower or comparable to the conventional one.