Method for reducing metal artifacts in CT images

A method for reducing metal artifacts in CT images, comprising the following steps:

• a material decomposition (MD) calibration step, using multiple MD calibration phantoms with known characteristics and multiple spectral CT data corresponding thereto to construct a system characteristic model of spectral CT;
• and
• a MD testing step, comprising:
• the following steps:
• imaging multiple testing objects with a different unknown material and thickness to obtain projection-based multiple spectral CT imaging data of different energy bins;
• obtaining corresponding multiple basis material images of different materials based on projection data according to said spectral CT imaging data and said system characteristic model of spectral CT, and substituting said spectral CT imaging data and said system characteristic model of spectral CT into a basis MD algorithm in the step of obtaining corresponding multiple basis material images of different materials based on projection data according to said spectral CT imaging data and said system characteristic model of spectral CT;
• and
• combining said basis material images and a photon energy information to be recombined with each other to obtain multiple virtual monoenergetic images.