【摘要】 目的:评价图像域迭代重建算法(iterative reconstruction in image space,IRIS)与滤波反投影法(filtered backprojection,FBP)对肝脏CT图像质量和扫描剂量的影响。方法:采用西门子emotion 16层螺旋CT,在上腹部常用扫描管电压130 kV条件下,曝光量分别采用250、230、210、190、170、150、130、110、90、70、50、30、20 mAs对尸体标本进行上腹部扫描,采用IRIS与FBP分别对扫描后的原始数据进行重建。以130 kV、250 mAs FBP重建图像作为对照,比较不同扫描剂量条件对肝脏图像质量的影响,探讨IRIS对降低肝脏CT扫描剂量、提高肝脏CT图像质量的作用。结果:在相同扫描条件下,IRIS重建图像质量优于FBP重建图像质量;在同等图像质量的前提下,IRIS可以降低40%的扫描剂量。结论:与FBP相比,IRIS可以显著降低扫描剂量,提高肝脏CT图像质量。更多还原

【Abstract】 Objective To evaluate image quality and radiation dose to liver CT scan with iterative reconstruction in image space(IRIS) compared to filtered back projection(FBP). Methods With Simens’ emotion 16-slice spiral CT and the tube voltage of 130 kV, the upper abdomens of the corpses were scanned with the exposure currents of 250, 230, 210, 190,170, 150, 130, 110, 90, 70, 50, 30 and 20 mAs. Then the raw scanning data were reconstructed with IRIS and FBP. The reconstructed images with 130 kV and 250 mAs by FBP were used to compare the influences on liver image quality by different scanning doses. The application of IRIS was explored to decreasing CT scanning dose and increasing liver CT image quality. Results Under the same scanning conditions, IRIS behaved better than FBP for reconstructed image quality, while reduced 40% scanning dose with the same image quality. Conclusion IRIS can decrease scanning dose and increase liver CT image quality more significantly than FBP.更多还原