Scatter Correction In Cone Beam CT Using Blind Deconvolution

Cone beam CT(CBCT)as the development of medical and industrial testing equipment in recent years,commonly used in image-guided treatment,upper abdominal examination,oral 3D reconstruction,industrial testing and so on.In the CBCT imaging system,CBCT reconstructed images are severely damaged by X-ray scattering,greatly reducing the visual effect of the image.Therefore,many researchers began to CBCT imaging process of scattering correction as their future research focus,has become the current hot issues.And this article on the hot issues to do a further study.Firstly,artifacts formed by scattering and beam hardening predominantly exhibit cupping artifacts and striped artifacts in the slice image.In medical-grade cone-beam CT,cupping artifacts occupy a large proportion of artifacts and is slowly varying CT value of the non-uniform artifacts in the entire image range.Therefore,this paper presents a new and fast scattering correction method,which belongs to the based-deconvolution correction method-deconvolution of the projection data.During the CBCT reconstruction,the cup artifacts are corrected as part of the scatter correction system,and are formed during the projection process.The analytical method of CBCT reconstruction method,such as filtered backprojection method and FDK algorithm,is introduced in detail for the scattered projection data obtained by the above method.Secondly,this paper proposes a scattering correction method to improve the image quality of CBCT-based on regularized blind deconvolution.The method can be roughly divided into three steps.First: the CBCT projection image pre-processing.The CBCT projection image is preprocessed.In this paper,two kinds of filters are mainly used.This facilitates the estimation of the convolution nuclei of the scattering core,while reducing the image noise while highlighting the edges of the image.Second: estimate the scattering core required for this method.In this step,we first use the pre-processed CBCT projection image obtained in the first step,and then use the regularization method to estimate the scattering kernel.Thirdly,the CBCT projection image is subjected to non-blind deconvolution.This step is mainly based on the TV regularization method and the second step to find the scattering core,and then non-blind deconvolution calculation.The most critical step in this approach is how to find scattered cores.In the above steps,in order to solve the model of the scattering kernel and the non-blind deconvolution model of the image,two algorithms are used,one is the fast iterative shrinkage threshold algorithm and the other is the fast total variational image restoration algorithm.This method is mainly for the scattering caused by the image caused by the phenomenon of degradation,image degradation once the doctor will diagnose a patient’s disease problems,delay treatment,in order to get the image before we need to restore the image The experimental results show that the artifacts of the images are reduced from 9.435% to 3.133%,and the contrast of the images is increased from 108.34 to 138.87,27.7%.Finally,this paper introduces the existing correction method and compares it with the method in this paper.The experimental results show a manual delineation confirmation demonstrated an improvement from 26% to 46 %.Therefore,it can be concluded that blind deconvolution of reconstructed PET images can be used to increase the accuracy of tumor presentation,and that the method is easy to achieve.