Morphological breast imaging: tomography and digital mammography with synchrotron radiation

A synchrotron radiation-based X-ray source offers a powerful tool for mammography due to the energy spectrum properties and the peculiar laminar beam geometry. 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 SR facility Elettra in Trieste (Italy). The detection system developed for digital mammography consists of a silicon pixel detector with 200×300 μm2 pixel size and high conversion efficiency. The detector is equipped with a low noise read-out electronics working in single photon counting mode. Mammographic phantoms and in vitro full breast samples have been investigated: the digital images show higher contrast resolution and lower absorbed dose than the images of the same samples obtained at the clinical mammographic unit.The SYRMEP collaboration is carrying out a breast tomography feasibility study to evaluate the image quality and the delivered dose. The SYRMEP beam is an ideal tool for tomography due to the laminar and monochromatic beam with negligible divergence. The experimental set-up and the acquisition protocol have been studied and the tomographic images of full breast samples acquired in the energy range 20–28 keV indicate that good quality images can be obtained with delivered doses comparable to conventional mammography.