An improved beam-hardening artifact correction method based on reprojection for CBCT

In Come-Beam computed tomography (CBCT),due to the wide energy spectrum of X-rays,serious beam hardening artifacts could exist in reconstructed images,which seriously interferes with experimental results. Therefore,it is necessary to correct the beam hardening artifacts. Among all kinds of correction methods,the beam hardening artifact correction method based on reprojection has been widely used because it does not need the prior information of materials. In order to improve the correction effect,this paper improves the existing correction method based on reprojection from three aspects:data preprocessing,data screening and correction model solving,which is susceptible to external factors in the correction process. Practical experimental results show that the proposed method can more effectively correct beam hardening artifacts,and the Contrast to Noise Ratio (CNR),cupping artifact index (Tcup) and Average Gradient (AG) are all improved to varying degrees.