Relative electron density determination using a physics based parameterization of photon interactions in medical DECT.

Radiotherapy and particle therapy treatment planning require accurate knowledge of the electron density and elemental composition of the tissues in the beam path to predict the local dose deposition. We describe a method for the analysis of dual energy computed tomography (DECT) images that provides the electron densities and effective atomic numbers of tissues. The CT measurement process is modelled by system weighting functions, which apply an energy dependent weighting to the parameterization of the total cross section for photon interactions with matter.

Feasibility and accuracy of tissue characterization with dual source computed tomography.

Purpose: To evaluate the feasibility and accuracy of a model for tissue characterization with dual source computed tomography (DSCT).

Methods And Materials: A model for tissue characterization in CT was used with a parameterization of linear attenuation coefficients. Sixteen chemical substances with effective atomic numbers between 5.