A novel decomposition method for Dual-energy Computed Tomography

Abstract

Dual-energy Computed Tomography (DECT) is a useful tool that has been used widely in the security field and clinical diagnosis, because of its outstanding capability of material identification. One of the widely used pre-reconstruction methods for DECT is dual effect decomposition method. But the method only takes the compton scattering and photoelectric effect into consideration and ignores other effects. Thus the dual effect decomposition method has large error and the reconstructed images also suffer from the decomposition error. In this paper, we proposed a new decomposition method for DECT. We use the mathematic method to decompose the linear attenuation coefficient matrix of the chosen materials within a fixed energy range. So we can obtain the basis functions and the material-dependent coefficients. Based on the two material-dependent coefficients, two different types of formula are fitted to calculate the atom number and electron density respectively. This method doesn't rely on any physical model and can decouple the interleaved information of material and energy as precisely as possible. Some experiments were conducted to indicate that our method works well in the DECT reconstruction.