Estimation of chemical composition and density from computed tomography carried out at a number of energies.

A method is presented by whichcomputed tomography scans carried out at a number of energies may be utilized to obtain cross-sectional images of density and atomic number in addition to the conventional array of linear attenuation coefficients. This type of analysis has been carried out for various substances of biological relevance. Computer simulated reconstructions of clinical situations suggest that the method shows promise for providing additional diagnostic information and might dispense to some extent with the necessity of injecting contrast agents into the patient.