A simple method for CT-Scanner calibration against effective photon energy

An original method for CT-scanner calibration against effective photon energy is presented. It is based on optimization of the CT-scanner output characteristic (the dependence of the measured linear attenuation coefficient on the calculated value). A significant gain in accuracy is achieved with respect to the calibration techniques which are conventionally used in commercial computed tomography. The method can be recommended for use in dual-energy computed tomography. As an example of its application, measurements of the effective atomic number and electron density of organic plastics are described. It is shown that the method provides acceptable results even for an increased noise level in CT images.