摘要
目的探讨双能CT物质分离技术在肝铁及脂肪共存状态下对肝铁及脂肪同时定量的可行性及精确性。方法选取56只新西兰兔进行高脂喂养及静注铁溶液以构建各级脂肪肝合并铁沉积的动物模型,采用双源双能CT进行肝脏扫描,通过多物质分离算法获得双能CT参数肝铁含量(Iron-CT)及肝脂肪含量(Fat-CT)。以病理脂肪含量(Fat-ref)及化学测试所得肝铁浓度(LIC)作为参考标准进行脂肪肝与铁过载分级。采用Pearson相关分析评估双能CT参数与金标准的关系。通过协方差分析联合线性回归评估双能CT铁与脂肪定量的相互影响。结果47只动物存活。肝铁定量参数Iron-CT值与LIC呈正相关(r=0.929,P<0.01);Fat-CT值与Fat-ref值呈正相关(r=0.862,P<0.01)。肝脂肪含量正常组、轻度脂肪肝组及中重度脂肪肝组Iron-CT与LIC的铁定量回归曲线斜率依次为2.818、2.381、2.783,协方差分析表明三者斜率无显著性差异(F=0.592,P>0.05)。肝铁含量正常组、轻中度铁过载组及重度铁过载组Fat-CT值与Fat-ref值的脂肪定量回归曲线斜率依次为0.6901、0.6256、0.3569,协方差分析表明随各组肝脏铁含量的升高,斜率降低,有显著性差异(F=5.989,P<0.05)。结论双能CT物质分离技术能够在铁及脂肪共存状态下分别对铁及脂肪进行定量评估,其中铁定量过程不受脂肪的影响,而脂肪定量可能由于铁过载而被低估。
Objective To assess the feasibility and accuracy of dual-energy CT(DECT)based on material decomposition technique for in vivo quantification of hepatic iron and fat in the state of coexisting steatosis and ironoverload.Methods Different levels of hepatic fat content animal models combined with various liver iron content were prepared by different diets with various doses of iron dextran injection in 56 New Zealand rabbits.Then each rabbit underwent an upper abdominal scanning on a dual-source DECT system.The data for each rabbit were reconstructed and post-processed by a multi-materials decomposition algorithm to obtain iron concentration(Iron-CT)and fat volume fraction(Fat-CT).The degrees of fatty liver and iron overload were classified according to fat content(Fat-ref)determined by pathological test and liver iron concentration(LIC)by chemical test.Pearson correlation analysis was performed between DECT parameters and standard reference.Covariance analysis combined with linear regression analysis was used to assess the influence of iron on fat quantification and the influence of fat on iron quantification.Results In 47 survived New Zealand rabbits,the Iron-CT values showed positively correlation with LIC(r=0.929,P<0.01).The Fat-CT values were positively correlated with Fat-ref(r=0.862,P<0.01).The regression slopes for iron evaluation between Iron-CT and LIC in normal liver fat content group,mild fatty liver group and moderate-severe fatty liver group were 2.818,2.381 and 2.783,respectively.Covariance analysis showed that there was no significant difference among the slopes of the three groups(F=0.592,P>0.05).The regression slopes for fat evaluation between Fat-CT and Fat-ref in normal liver iron content group,mild-moderate iron overload group and severe iron overload group were 0.6901,0.6256 and 0.3569 respectively.Covariance analysis showed the regression slopes decreased significantly in groups with higher iron concentrations(F=5.989,P<0.05).Conclusion Material decomposition technique of DECT allows for quantification of liver iron and fat content simultaneously in the state of coexisting of fat and iron.Iron quantification willnot be influenced by fat,while elevated liver iron may lead to fat underestimate.
作者
彭云
刘畅
贾宏茹
吴晶涛
罗先富
PENG Yun;LIU Chang;JIA Hongru(Department of Radiology,Northern Jiangsu Peopled Hospital,Clinical Medical School of Yangzhou University,Yangzhou,Jiangsu Province 225001,P.R.China)
出处
《临床放射学杂志》
北大核心
2021年第8期1616-1620,共5页
Journal of Clinical Radiology
基金
江苏省青年基金项目(编号:BK20160450)
江苏省“六大人才高峰”项目(编号:2016-WSN-277)
江苏省青年医学重点人才项目(编号:QNRC2016321)
扬州市医学重点人才项目(编号:48)
国家自然科学基金资助项目(编号:81571652)。
关键词
双能CT
物质分离
脂肪定量
铁定量
Dual-energy CT
Material decomposition
Fat quantification
Iron quantification
