Quantitative comparison of dual-energy CT and differential phase contrast CT imaging methods

The purpose of this study is to evaluate and compare the quantitative imaging performance of the dual-energy CT (DECT) and differential phase contrast CT (DPCT). The electron density (rho(e)) and the effective atomic number (Z(eff)) are selected as the two comparison bases for the DECT and DPCT imaging. From the numerically simulated data, image domain based decomposition algorithms are used to extract the rho e and Z(eff) information for three different spatial resolution levels (0.3 mm, 0.1 mm, and 0.03 mm). The contrast-to-noise-ratio (CNR) and modeled human observer studies have been investigated to compare the DECT and DPCT quantitative imaging performance. At low spatial resolution (0.3 mm), the DECT shows better quantitative imaging performance than DPCT. As a contrary, the DPCT outperforms the DECT for ultra high spatial resolution (0.03 mm) imaging. With the 0.1 mm spatial resolution, the DECT and DPCT shows similar quantitative imaging performance. In conclusion, the DECT is more favored for low spatial resolution applications, such as the diagnostic imaging tasks. However, the DPCT would be recommended for ultra high spatial resolution imaging tasks, such as the micro-CT imaging tasks.