Final Activity Report Summary - B-SCATTO (SCATter computed TOmography of the Breast: "in vitro" tests and assessment of clinical feasibility) The project aimed at assessing the diagnostic capability of X-ray diffraction computed tomography (XRDCT) in its breast imaging application and, in particular, at evaluating its capability of discriminating different types of lesions. Several approaches were considered, combining different detection devices, geometries and X-ray spectra. The most successful approach in terms of information content was an energy-dispersive system based on the use of a spectroscopic, single photon counting detector which allowed complete diffraction patterns to be extracted following the acquisition of low-statistics spectra. This technique allowed to identify several families of diffraction patterns corresponding to different tissue types with different levels of healthy tissue invasion by cancerous cells. The comparison with conventional, i.e. transmission, Computed tomography (CT) showed that, in spite of the poorer spatial resolution, XRDCT allowed for discrimination of structures having the same X-ray attenuation coefficient, hence showing the same average grey level in transmission CT. Furthermore, data acquired with the Energy-dispersive (ED) technique were compared to data obtained with monochromatic synchrotron radiation. Despite the higher intensity of a synchrotron beam EDXRDCT data featured higher information content, thus encouraging the development of laboratory-based techniques rather than techniques based on large facilities. Even though the XRDCT technique was unlikely to be applied 'in vivo' in the immediate future due to the strict constraints in terms of acquisition times and patient dose, it appeared very promising for 'in vitro' tissue characterisation to complete the information provided by breast biopsy. In particular, the dependence of the diffraction signal on the tissue arrangement at the molecular level suggested that EDXRDCT could provide information on changes occurring at the early stages of tumour formation, thus appearing a promising tool for early diagnosis of breast cancer.
