O espalhamento Compton de raios X no diagnóstico de neoplasias mamárias

Abstract

ANTONIASSI, M. The Compton scattering of X-rays in the diagnosis of breast neoplasia. [thesis]. Ribeirao Preto: Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo; 2012. 102p. In this work we have been measured elastic and inelastic scattering from normal and neoplastic (benign and malignant) breast tissues using a photon energy of 17.44 keV (Kα radiation – Mo) and a scattering angle of 90o in order to determine the electron densities (ρe), effective atomic number (Zef) and full width at half maximum (FWHM) of inelastic peak of these tissues. Compton scattering imaging techniques was also studied using computational simulation. The experimental methods were checked by analyzing of standard reference materials. The values of electron densities and effective atomic numbers obtained were compared with theoretical and experimental data previously published, showing good agreement between them (differences smaller than 5%). The values of FWHM indicate the possibility of using the FWHM for obtain information about the composition of tissues showing correlation with the values of Zef. The results also show that there are differences of ρe, Zef and FWHM between groups of tissues which are associated with the composition and histology of the investigated tissues. Finally, the results of the study of the Compton scattering imaging technique allowed assessing the influence of various factors, related to the radiation beam, geometry sample, which determine the image quality.