CAJ | 학술논문

常规固定电压的 CT 重建，因成像系统动态范围受限，投影数据易出现过曝光和欠曝光共存现象，造成信息缺失多，成像质量差，为此提出变电压 CT 重建。通过变电压获得跟工件有效厚度相匹配的有效投影序列，在 ART 迭代图像的基础上，调整全变差使其最小化，从而优化重建。在重建过程中，依据灰度加权，把低电压的重建图像作为初值，应用在相邻高电压有效投影重建中，得到相邻高电压的重建图像，依次类推直至最高电压。至此，工件的全部结构信息重建完毕。仿真结果表明，灰度加权算法不仅实现了变电压图像信息的完整重建，而且像素值更加稳定。
상규고정전압적 CT 중건，인성상계통동태범위수한，투영수거역출현과폭광화흠폭광공존현상，조성신식결실다，성상질량차，위차제출변전압 CT 중건。통과변전압획득근공건유효후도상필배적유효투영서렬，재 ART 질대도상적기출상，조정전변차사기최소화，종이우화중건。재중건과정중，의거회도가권，파저전압적중건도상작위초치，응용재상린고전압유효투영중건중，득도상린고전압적중건도상，의차유추직지최고전압。지차，공건적전부결구신식중건완필。방진결과표명，회도가권산법불부실현료변전압도상신식적완정중건，이차상소치경가은정。
In conventional computed tomography (CT) reconstruction based on fixed voltage ,the projective data often ap-pear overexposed or underexposed ,as a result ,the reconstructive results are poor .To solve this problem ,variable voltage CT reconstruction has been proposed .The effective projective sequences of a structural component are obtained through the variable voltage .The total variation is adjusted and minimized to optimize the reconstructive results on the basis of iterative image using algebraic reconstruction technique (ART) .In the process of reconstruction ,the reconstructive image of low voltage is used as an initial value of the effective projective reconstruction of the adjacent high voltage ,and so on until to the highest voltage according to the gray weighted algorithm .Thereby the complete structural information is reconstructed . Simulation results show that the proposed algorithm can completely reflect the information of a complicated structural com -ponent ,and the pixel values are more stable than those of the conventional .