双能CT不同能量组合、重建算法及ROI选择对家兔肝铁定量测量的影响  

Research on the effects of various energy combination,reconstruction algorithms,and ROI selection of dual-energy CT on the quantification of iron in rabbit livers

作　　者：许霄 黄求理[1] 朱雪君[1] 李涛[2] 曹迪[2] 龙莉玲[2] XU Xiao;HUANG Qiu-li;ZHU Xue-jun(Department of Radiology,the First Hospital of Ningbo,Zhejiang 315000,China)

机构地区：[1]宁波市第一医院放射科,浙江315000 [2]广西医科大学第一附属医院放射科,南宁530021

出　　处：《放射学实践》2018年第4期344-348,共5页Radiologic Practice

摘　　要：目的:探讨双能CT不同能量组合、重建算法及ROI选择对家兔模型肝脏铁定量检测的影响。方法:健康雄性新西兰大白兔32只,每周按15mg/kg的剂量肌肉注射右旋糖苷铁剂,共16周,每周处死2只大白兔,使用原子分光光度仪测量肝脏的铁浓度(LIC)。采用80+140kVp和100+140kVp两种能量组合进行双能CT扫描,在80+140kVp组合条件下分别采用滤波反投影法(FBP)和迭代重建算法(SAFIRE)算法(强度为3)进行图像重建,对3组图像数据分别进行图像后处理获得虚拟铁浓度图像(VIC),分别采用全肝ROI法和小ROI法测量肝脏的CT值,分别对3组图像及2种ROI法测量的肝脏CT值进行比较,并与LIC行Spearmen相关性分析。结果:对2种能量组合及2种ROI方法测量的VIC图像上肝脏的CT值进行比较,差异均有统计学意义(P<0.01);两种重建算法下测得的VIC图像上肝脏CT值的差异无统计学意义(P>0.05)。采用80+140kVp、SAFIRE算法及全肝ROI法测得的VIC图上肝脏CT值与LIC的相关性分别优于100+140kVp、FBP算法及小ROI法。结论:双能CT扫描可获得肝脏虚拟铁浓度图像,不同能量组合、重建算法及ROI测量方法获得的肝脏CT值均能反映家兔肝脏铁含量,但以80+140kV和全肝ROI法更优,不同的重建算法不影响测量值的大小。Objective:To explore the effect of dual-energy CT combination,reconstruction algorithm and ROI selection on quantitative detection of liver iron of rabbits.Methods:32 healthy New Zealand male white rabbits from were injected with dextran iron supplements of 15mg/kg per week for 16 weeks.Per week two rabbits were accepted dual-energy scanning using 80/l40kVp and 100/l40kVp and were sacrificed for pathologic examination for calculating liver iron concentration(LIC).Under 80/l40kVp combination conditions,the filtered back projection(FBP)method and sinogram affirmed iterative reconstruction(SAFIRE)based on the original data with the intensity of 3 were used for reconstruction.The whole-liver ROI method and the small ROI method were used to measure the CT value on virtual iron concentration(VIC)images postprocessed from dual-energy scanning data,and then the CT value of liver on VIC images under different conditions were compared and statistically analyzed for correlation with the LIC using Spearmen correlation analysis.Results:The differences in CT values on the VIC images between two energy combinations and ROI methods were statistically significant(P<0.01);while the difference of CT values between VIC images using two reconstruction algorithms was not statistically significant(P>0.05).The correlation between CT value of VIC images and LIC of 80/140kVp,SAFIRE and whole-liver ROI method was better than that of 100/140kVp,FBP and small ROI method respectively.Conclusion:CT value of VIC images obtained by two energy combinations,reconstruction algorithm and ROI measurement method can indicate liver iron concentration,80/140kVp and whole-liver ROI method are better,and the measured value will not be affected by different reconstruction algorithms.

关 键 词：双能CT 肝脏 铁代谢 重建算法 感兴趣区 

分 类 号：R814.42[医药卫生—影像医学与核医学]