Research On X-ray Beam Hardening Correction Method In CT Images

X-ray tomography is a new technology developed in the 1870s and is currently widely used in medical diagnosis and industrial nondestructive testing.This technology uses the material's ray attenuation characteristics to obtain projection data from different angles,and obtains a tomographic image of the object after reconstruction.This technology can realize the detection of its internal structure and organizational properties without causing damage to the measured object itself.However,in the actual CT scanning system,the obtained scan data usually has a certain error.These errors are mainly caused by some noises,beam hardening effects,and metal objects.At this time,artifacts will appear in the reconstructed image,which seriously affects the quality of the image.When the measured object contains high-attenuation metal parts(such as surgical clips,dental fillers and artificial joints,etc.),metal artifacts will be introduced into the reconstructed image,which is caused by various physical effects,and the beam Hardening is the main factor.In response to the introduced artifacts,this paper analyzes the principle of artifact formation,and develops and implements a metal artifact correction method and a beam hardening artifact correction system.The main methods are:(1)A first Metal artifact correction method based on the combination of image verification and adaptive full variational filtering.This method can better reduce metal artifacts;(2)A radiation method that uses the relationship between the approximate material attenuation coefficient and X-ray energy is proposed.The beam hardening correction method can remove artifacts and retain the information in the original image.The method mainly includes acquiring metal areas,acquiring projection data,approximating artifact data,and acquiring corrected images.Through numerical experiments,the method proposed in this paper is compared with other algorithms.The experimental and simulation data show that the reconstructed image obtained by the metal artifact correction method and beam hardening correction system proposed in this paper can better remove artifacts and retain the original The details in the picture.Among them,the beam hardening correction system does not require a priori knowledge.This system suppresses the strip artifacts around the metal to a certain extent,the edge details of the reconstructed image are guaranteed,and the quality of the reconstructed image is also improved.