Contrast agents with high-Z elements have K-absorption edges which significantly change X-ray attenuation
coefficients. The K-edge characteristics is different for various kinds of contrast agents, which offers opportunities for
material decomposition in biomedical applications. In this paper, we propose a new K-edge imaging method, which not
only quantifies a distribution of a contrast agent but also provides an optimized contrast ratio. Our numerical simulation
tests demonstrate the feasibility and merits of the proposed methodology.