The Simulation Design Of Energy Spectrum CT Imaging System Based On Dual-layer Plane Flat Detector

The routine CT can only reconstruction of linear attenuation coefficient,there may be a bigger error,while the energy spectrum CT could rebuild the material effective atomic number and the electron density,then has the ability of material resolution,and can effectively solve the problem such as beam hardening and metal artifacts.Therefore,the energy spectrum CT is the development direction of CT in future,both in the field of security and health will have great development and application.But,due to energy spectrum CT equipment is expensive,and key technologies are controlled by a few several big international companies,it is hard to access the actual energy spectrum CT study,therefore,choose from the simulation,and compared from energy spectrum CT basis of dual-energy CT based on double digital flat panel detector,study on simulation of energy spectrum CT system.GATE developed in this paper based on the Monte Carlo simulation method are used to design the simulation.Analyzed mainly from three aspects:the source of CT system,phantom and double digital flat panel detector.the design and parameter design of double digital flat panel detector chosen by crystal,reaction depth,detection efficiency and attenuation layer analysis,and gives a design scheme of dual-energy CT imaging system,lay a theoretical foundation for the research of energy spectrum CT.In this paper,designed several experiments to get the simulation data based on the energy spectrum CT.This paper presents a processing method and the process based on the simulation data,and the different layer of the detector receives the projection of the data were analyzed.In addition,from the aspects of dual-energy subtraction angiography and FDK reconstruction,processing of simulation data analysis,this thesis design is verified the feasibility of the energy spectrum of CT system.In the end of this paper,designed a related experiments,calculate the quality attenuation coefficient based on narrow beam X-ray,and compared with the data of the XCOM standard database published by NIST(The National Institute of Standards and Technology).The result verified that The GATE simulation platform to simulate particle transport process,The feasibility of The accuracy of mass attenuation coefficient calculation are also verified,at The same time also shows that we can use a GATE to simulate The energy spectrum CT.