Multi-Spectrum CT Imaging Method Based On The Spectrum Matching Priors

In the process of X-ray computed tomography imaging,the traditional single-energy X-ray CT imaging technology is only applicable to structural analysis but can't meet needs of function for substance distinction and identification because of the multispectral hardening artifacts and inconsistency between the projection acquisition process and reconstruction assumption.For the multi-spectrum CT imaging method based on energy spectrum filtering separation,which can overcome the inconsistency between multi-energy projection and single energy reconstruction,obtain the similar energy spectrum by filtering and distinguish materials of objective,but the traditional method can't distinguish.Due to the limitation of the normal imaging of the detector,there are some limitations in obtaining narrow band.First,construct energy spectrum filtering matching model,set range spectrum parameters according to the material composition and get multi-spectrum projection sequence by filtering;In view of the pluripotent projection sequence,a reference energy is introduced to improve the multi-energy projection expression and a multispectral CT imaging method based on the spectrum matching priors is presented.The feasibility of the reconstruction algorithm is verified by simulation and experiment,and the effective separation of various materials is realized by different reference energy selection.Finally,based on the EM reconstruction algorithm,the reference energy is also introduced to improve the X-ray statistical model,and a multi-energy EM reconstruction algorithm based on reference energy is deduced by using the maximum likelihood estimation method,the feasibility and validity of the algorithm are verified by simulation and experiment.The results show that the method can effectively distinguish the similar materials in the case of high noise level by different reference energy selection.