Liver Iron Quantification By Computed Tomography In Iron-overloaded Rabbit

Objective:To explore the accuracy of the Single-energy Computed T omography(SECT)and Dual-energy Computed Tomography(DECT)quantitative diagnosis,which is CT value in liver iron deposition.Materials and Methods:33 adult male New Zealand white rabbits,with the weight of 2.0kg to 2.9kg,31 rabbits underwent iron dextran loading from 1-21 weeks,and 2 rabbits were normal.All the rabbits weighed for the dose of iron(150mg/ml).The rabbits weekly injected iron with the dose of 100mg/kg,altogether 21 weeks.Every week,the experimental group undergone the SECT(120kV)and DECT after the injection of iron,and then were killed for the liver.The part of liver was selected for pathological diagnosis,and the remaining liver was dried for liver iron concentration(LIC).After SECT and DECT examination,the normal rabbits were killed for pathological diagnosis and LIC.Analysed the relevance between LIC or hepatic iron content and the dose of the Injected iron,LIC and CT(120kV.DECT),and set up the linear regression equation.Results:Experimental group's LIC ranged from 4.2?73.7mg/g dry tissure,median was 42.2mg/g dry tissure.There was apparent linear relationship between LIC and the total iron injection(r=0.899,P=0.000).Linear regression equation was seted up:Y = 0.009X + 11.328(Y:LIC,X:the total iron)(F =80.082,P = 0.000).There was apparent linear relationship between total liver iron and total iron injection(r=0.950,P=0.000).Linear regression equation was seted up:Y?0.369X+ 119.731(Y:total liver iron,X:the total dose of iron)(F =176.153,P=0.000).There was linear relationship between unit volume iron and total liver iron(r=0.961,P = 0.000).Linear regression equation was seted up:Y=1.100X + 46.199(Y:total liver iron,X:unit dose of iron)(F = 230.855,P =0.000)?The differences of CT values measured by two radiologists are not statistically significant(p>0.05).There was apparent linear relationship between LIC and the SECT(120kv)value(r=0.980,P =0.000).Linear regression equation was seted up:Y=0.584X-30.530(Y:the predicted LIC,X:the SECT(120kv)value)(F=453.201,P=0.000).There was apparent linear relationship between LIC and the DECT value(r=0.986,P =0.000).Linear regression equation was seted up:Y=0.368X-2.258(Y:the predicted LIC,X:the CT value)(F=647.409,P=0.000).In the 10 test rabbits,the predicted LICs using the equations agreed well with the results obtained using spectrophotometer.Conclusion:DECT and SECT quantification of liver iron overload is feasible within a certain LIC(4.2?73.7mg/g dry tissure).What's more,MRI showed limitations above 43mg/g dry tissure.