Simulated intensity profiles for cylindrical objects in magnification mammography: the effect of the spectrum

Resumo

We present a user-friendly Matlab simulation interface tool to predict intensity profiles for magnified X-ray images of weakly attenuating cylindrical objects, including phase effects. Based on a previous monoenergetic formalism, we now consider polyenergetic X-ray beams and we study the effect of the spectral description on the predicted phase contrast. It was found that, for weakly attenuating objects with diameters <≈1 mm, detailed resolution in the spectrum description is not necessary. Simulations are compared with images of cylindrical objects, which were obtained under conditions found in a commercial digital mammography system. The magnification images of phantom plastic fibers show weak, however visible, edge enhancement due to phase contrast. The polyenergetic simulations provide an improved description of the data with respect to the effective energy monoenergetic assumption.