Application Of Dual-Energy CT Equilibrium Phases Quantification Of Extracellular Volume Fraction In Liver Cirrhosis And Esophageal Varices

Objective:To investigate the optimal scanning phase for evaluating the severity of liver cirrhosis by measuring extracellular volume fraction with dual-source CT.Methods:Sixty-one patients with cirrhosis and forty-one healthy volunteers were enrolled.All subjects underwent dual-source CT scanning.About 25 s and 60 s after contrast injection,the arteriovenous phase images were obtained by scanning,and the interval between the two delayed images and the arterial phase scan was 3min and 5min,respectively.Esophagogastroduodenoscopy was performed in 38 patients with cirrhosis.The correlation between f ECV and endoscopic grade of EV was calculated and compared between high-risk varices group and non-high-risk varices group.The receiver operator characteristic curve was drawn and compared.Results:The accuracy of f ECV scores obtained in patients with cirrhosis was similar at 3 and5 min delay(P=0.083).The f ECV in both stages was positively correlated with Child-Pugh stage(rs=0.432 P=0.001 VS rs=0.416 P=0.001),and the correlation coefficient was higher than the normalized iodine concentration,and f ECV in cirrhosis group was significantly higher than that in control group(P < 0.001).One-way ANOVA showed that there were statistically significant differences between the control group and Child-Pugh grade,and between the Child-Pugh grade A and Child-Pugh grade C(P <0.05).There was no significant difference in f ECV between the two time points(P =0.083).The AUC of f ECV in the 5-minute delay period was the highest(AUC = 0.938),and the diagnostic ability of f ECV for liver cirrhosis was higher than that of normalized iodine concentration.The difference was statistically significant(P < 0.05).The fecv was only weakly positively correlated with the grade of EV(rs=0.365 P=0.024 VS rs=0.345P=0.034).One-way analysis of variance showed that f ECV of EV0,EV1 and EV2 were significantly different between the two phases(P < 0.05).There were statistically significant differences in f ECV between high-risk varicose vein group and non-high-risk group at different periods(P =0.005 VS P =0.003).The AUC of f ECV to exclude high-risk varicose veins were 0.775 and 0.769.Conclusion:Extracellular volume fraction assessed on dual-energy CT at equilibrium phases with different timing was substantially similar.The f ECV can provide important information for the evaluation of the severity of liver cirrhosis and EV,and has certain reference value for clinical treatment.