Beam hardening correction method for Cone-Beam computed tomography based on reprojection of slice contours

According to the principle of beam hardening in Cone-Beam Computed Tomography (CBCT), a new beam hardening correction method for CBCT based on re-projection of slice contours is presented. Firstly, contour information of center slice and aslant slice are acquired from the serial slice images that reconstructed from original projection images, then the re-projection coordinates are set up by using the practical scan parameters of CBCT imaging system. After that, the numerical relation between the length of X-ray traversing object and the value of projection gray is founded by re-projecting the contours to the flat panel detector. Finally, an exponential function is designed for fitting the beam hardening curve and made use of correcting beam hardening artifact. The experimental correction results of both simulation and practical scan show that the method can mostly remove the beam hardening artifact in CBCT simply and effectively.