SAFIRE与FBP重建法对CT图像噪声及扫描剂量影响的比较研究

摘要

Objective To evaluate image noise and potential radiation dose reduction of Sinogram affirmed iterative reconstruction (SAFIRE) as compared to filtered back projection (FBP). Methods With 128-slice dual-source CT, 120 kV, 100 kV, 80 kV, 70 kV tube voltage, 200 mAs, 170 mAs, 140 mAs, 110 mAs, 80 mAs, 50 mAs, 20 mAs were employed in every section respectively, phantom images were reconstructed with SAFIRE reconstruction algorithm from one to five iterations and FBP reconstruction algorithm, compare image noise and analyze radiation dose saving potential. Results SAFIRE algorithm provide similar image quality compared with the conventionally used FBP algorithm at 120Kv 45% ~ 75% less dose, 100 kV 45%~75% less dose, 80kV 45%~60% less dose, 70kV 15%~60% less dose. Conclusion SAFIRE reconstructions have the potential to reduce radiation dose at 15%~75% without deterioration in image quality.%目的 评价应用原始数据迭代重建法(SAFIRE)与滤波反投影法(FBP)对CT图像噪声及扫描剂量的影响.方法 应用128层双源Flash CT,在120kV、100kV、80kV、70kV条件下,分别采用200mAs、170mAs、140mAs、110mAs、80mAs、50mAs、20mAs扫描剂量扫描水模,采用原始数据迭代重建法与滤波反投影法分别重建,不同管电压条件下,以预设扫描管电流200mAs FBP重建图像作为对照,比较不同扫描剂量、不同重建方法图像噪声并分析扫描剂量降低的潜力.结果 原始数据迭代重建法随着迭代次数的增多,120kV管电压时降低45％～75％的扫描剂量,100kV管电压时降低45％～75％的扫描剂量,80kV管电压时降低45％～60％的扫描剂量,70kV管电压时降低15％～60％的扫描剂量,可以得到与200mAs FBP重建法噪声无统计学差异的图像.结论 SAFIRE重建法与FBP重建法比较可以显著降低图像噪声,从而降低扫描剂量并同时得到满意图像.