Method for the determination of electron density from multi-energy X-ray CT

We propose a method for estimation of material's electron density parameter (ρ_e) using multi-energy x-ray Computed Tomography (CT). Multi-energy CT uses a photon counting detector (PCD) to measure a material's linear attenuation coefficient (LAC) at multiple energies with the simultaneous data acquisition. The physical effects in the PCD such as charge sharing and photon pileup result in spectral distortions of the energy spectrum. Corrects for such distortions are performed with a correction algorithm. A custom laboratory instrument for multi-energy CT is used to experimentally validate the method. The identification efficiency is evaluated for different numbers of energy channels. When using 15 energy channels without inter-gaps the method gives a relative deviation of 1.8% for estimation of ρ_e, for materials in the range of 0.43≤ρ_e≤1.06e⁻mol/cm³.