Research On Characterization Algorithm Of Multi-energy CT Components Based On Reference Components

The characterization of material components is of great importance to the physicochemical properties and applications of the materials studied.When the components of the material are characterized by CT,since the X-ray generated by the conventional CT machine is a continuous spectrum,the acquired multi-energy projection data is inconsistent with the reconstruction algorithm based on the single-energy hypothesis,so that the reconstructed image has more hardening artifacts,resulting in It is difficult to distinguish the components of the material effectively.The emergence of synchrotron radiation sources presents new opportunities for material composition characterization.The synchrotron radiation source has good monochromaticity,and the reconstructed image quality is significantly improved compared with the conventional CT,and the material composition can be more accurately characterized.However,its cost is expensive,it is a large scientific device of the country,and the sharing surface is wide,which cannot meet the experimental needs of a certain scale.Therefore,in view of the existing CT system,this paper draws on the idea of DCM model decomposition based on synchrotron radiation source,and studies the multi-spectral CT characterization based on reference components to realize the differentiation of material components.Firstly,the paper analyzes the attenuation coefficient-energy curve of each component of the material,selects the component with faster decay rate as the reference component and makes the single component of the reference component.After selecting the appropriate voltage,the voltage is obtained.The projection of the material and the reference component material is then reconstructed using a single energy reconstruction algorithm for the material under each voltage and the projection of the single material motif.The corresponding attenuation coefficient values are calculated according to the reconstruction maps of the reference components at respective voltages,and the energy corresponding to the attenuation coefficient values of the reference components is calculated by the cubic spline interpolation method,and the attenuation coefficient values of the other components are obtained according to the determination.Finally,the multi-energy decomposition algorithm is used to decompose and obtain the decomposition map of each component of the material.The experimental results show that the reference component-based calculation method studied in this paper is feasible.However,the method is a two-step algorithm,which is divided into two steps of reconstruction and decomposition.In the case of complex components,the accuracy is difficult to guarantee.In response to this problem,this paper studies a one-step algorithm to directly obtain an exploded view from the projection.The paper first gives the objective function of the problem,and then derives the onestep algorithm of this paper based on the geometric interpretation of the algebraic iterative reconstruction algorithm.Finally,the convergence of the algorithm is studied by simulation experiments,and its application research is carried out.The simulation results show that this algorithm can be applied to multi-energy CT by energy spectrum filtering.