CAJ | 학술논문

X射线薄板层析成像（CL ）系统是一种针对板状构件的新型断层成像系统，该系统中存在射束硬化现象。本工作研究了一种基于SART算法的硬化伪影校正算法（SART-BHC算法），通过对该算法的研究及对CL系统矩阵的计算，使该方法能应用于CL中。通过模拟与实验相结合的方式，利用蒙特卡罗方法获得CL投影的模拟数据，在实际CL中获得实验数据，然后利用SART-BHC与 FPB算法对两种数据分别重建。结果表明，SART-BHC算法可应用于CL中，不需要任何先验知识，能很好地校正硬化伪影，并对层间混叠有抑制作用。
X사선박판층석성상（CL ）계통시일충침대판상구건적신형단층성상계통，해계통중존재사속경화현상。본공작연구료일충기우SART산법적경화위영교정산법（SART-BHC산법），통과대해산법적연구급대CL계통구진적계산，사해방법능응용우CL중。통과모의여실험상결합적방식，이용몽특잡라방법획득CL투영적모의수거，재실제CL중획득실험수거，연후이용SART-BHC여 FPB산법대량충수거분별중건。결과표명，SART-BHC산법가응용우CL중，불수요임하선험지식，능흔호지교정경화위영，병대층간혼첩유억제작용。
Computed laminography (CL) is a non-destructive testing technique for large objects ,especially for planar objects .Beam hardening artifacts were wildly observed in the CL system and significantly reduce the image quality .This study proposed a novel simultaneous algebraic reconstruction technique (SART ) based beam hardening correc-tion (BHC) method for the CL system ,namely the SART-BHC algorithm in short .The SART-BHC algorithm took the polychromatic attenuation process in account to formu-late the iterative reconstruction update .A novel projection matrix calculation method which was different from the conventional cone-beam or fan-beam geometry was also studied for the CL system .The proposed method was evaluated with simulation dataand experimental data ,which was generated using the Monte Carlo simulation toolkit Geant4 and a bench-top CL system ,respectively .All projection data were reconstructed with SART-BHC algorithm and the standard filtered back projection (FBP) algorithm . The reconstructed images show that beam hardening artifacts are greatly reduced with the SART-BHC algorithm compared to the FBP algorithm .The SART-BHC algorithm doesn’t need any prior know-ledge about the object or the X-ray spectrum and it can also mitigate the interlayer aliasing .