Liver Iron Overload Quantitative Assessment By Fast-kilovolt-peak Switching Dual-energy CT

Objective To explore the feasibility of liver iron deposition quantification by using fast-kilovolt-peak switching dual-energy CT and whether different scaning conditions have an impact on the measurement results.Methods The iron overload model was established by intramuscular injection of different doses of iron dextran in 10 experimental rabbits.All rabbits were scanned by GE Revolution CT 256 slices scanner in GSI mode with rapid tube voltage switching between 80 and 140 kvp and with tube current 200 m A,240 m A,320 m A respectively.On post-processing workstation,all images of iron（water）-based substance pair were reconstructed and the virtual iron concentration（VIC）value were recorded.After examination the rabbits were sacrificed,assessments of liver iron concentration（LIC）were measured with microplate reader and a portion of liver speciments were analyzed by Prussian blue staining.The correlation between VIC and the actual liver concentration（LIC）of the three sets of tube currents（200m A,240 m A,320 m A）was analyzed by spearman correlation analysis and linear regression.In addition,VIC of the three sets of tube currents was compared with the Kruskal-Wallis rank sum test.Results The range of LIC measured by microplate reader is 5.67 ～ 202.16 mg Fe / g wet weight.VIC was highly positively correlated with LIC under different tube currents（r2value was0.994,0.982,0.964,respectively p<0.05）.Kruskal Wallis rank sum test χ2= 1.374,P=0.53>0.05.Prussian blue staining showed that with the increase of iron injection of dextran,the more iron was deposited in the liver and distributed more widely.Coclusions VIC value of the fast-kilovolt-peak switching dual-energy CT can be used to accurately quantify liver iron accumulation and there ie no significant difference between different tube currents.