A Correction Method for Hardening Artifacts in CT Images Based on Integral Invariance
LIU Yuxin
WEI Jiaotong
ZHAO Xiaojie
CHEN Ping
PAN Jinxiao
Abstract：In conventional computed tomography(CT)systems,X-ray beams used for imaging are polyenergetic.These beams cause hardening artifacts in the reconstructed images owing to their polychromatic nature.For a multi-material imaging object,prior information about the X-ray spectrum and composition of the imaging object is required for correcting the beam hardening.To avoid relying on such prior information,this study proposes a beam-hardening artifact correction method for CT imaging of multi-material objects under single voltage.In this method,the X-ray image is considered as a non-negative weighted sum of multiple single-energy X-ray images.The decomposition model for the X-ray transmission images is constructed using the maximum likelihood function of a Gaussian distribution as the objective function under the constraint of the projection integral invariance at different angles.To solve this model,the projection of the spatial terms on the X-ray path is obtained.Thus,CT images for X-ray beams with different energies can be reconstructed.For imaging experiments with dual-material and multi-material models,compared with directly reconstructed CT images,the hardening artifacts in the reconstructed images were significantly reduced using this method,indicating its effectiveness.
Keywords：single voltageintegral invariancebeam hardening correctionwithout prior informationmulti-materials
Publication Date：2025-07-31
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 571-579 )