Material discrimination study of dual-energy imaging using photon counting detector

Photon counting detectors with electronic spectrum splitting, such as cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detectors have been widely used in x-ray imaging. We research the feasibility of material discrimination using dual energy imaging with CZT photon counting detector. The initial x-ray spectrum is from the X-ray tube with a voltage of 160 kVp, and the x-ray spectrum is calculated by Monte-Carlo method. A linear CZT detector with 32 pixels was used and an experiment with different materials was conducted. For each scanned object, three images under different photon energies are obtained simultaneously. We chose two of them for dual-energy imaging. A method of material discrimination is presented, using transmission data in different energy regions, we can calculate the atomic number of them. The results show its feasibility and possible of material discrimination using this kind of energy resolving detector. Compared with the typical dual-energy imaging system, this method can achieve higher precision. Using dual-energy imaging method, photon counting detectors can be used in explosive detection and luggage screening, which is proved to be effective.