The Clinical Value Of Hepatic Extracellular Volume Fraction Using Routine Multiphasic Contrast-enhanced Liver CT For Staging Hepatic Fibrosis

Objective: To investigate the value of hepatic extracellular volume fractions(fECVs)measured using multiphasic contrast-enhanced routine liver computed tomography(CT)evaluating and staging hepatic fibrosis(HF).Methods: A total of 60 patients(male-female ratio, 39:21; mean age, 42.4 years) met the inclusion and exclusion criterias who underwent both liver biopsy and multiphasic contrast-enhanced routine liver computed tomography(CT). Absolute enhancements(in Hounsfield unit) of the liver parenchyma(Eliver) and aorta(Eaorta) 3 minutes after contrast administration were calculated using precontrast and equilibrium phase scans. The fECV was calculated using the following equation: fECV(%) = Eliver/Eaorta(100- Hematocrit[%]).Continuous variables were expressed as mean ± standard error. Correlation between fECV and HF stage was evaluated using the Spearman correlation coefficient. The fECVs were compared between each stage of hepatic fibrosis. Diagnostic performance and cutoff values of fECV for staging hepatic fibrosis were assessed using receiver operating curve analysis(ROC).All statistics were calculated with the SPSS software(version 19.0). A value of p <0.05 was considered significant.Results: The fECV was observed to significantly increase as fibrosis progressed(S0,26.72±3.74%; S1, 30.16±5.71%; S2, 30.92±5.91%; S3, 34.80±6.70%; and S4, 41.56±11.48%).The difference among the groups was statistically significant(F=4.50, P<0.05). The fECVs were significantly different(P<0.05) between S0 versus S4、S1 versus S3、S1 versus S4 and S2 versus S4.The fECVs showed a significant correlation with pathologic HF staging(r = 0.468, P = 0.001).The sensitivity and specificity for severe HF and early liver cirrhosis(S≥3 and S=4) were 0.76 and0.68, 0.89 and 0.63, respectively. The AUROC for S≥3 and S=4 were 0.757 and 0.775,respectively. The cutoff for S≥3 and S=4 were 31.95% and 32.74%, respectively.Conclusion: Because fECV was shown to increase along with HF progression and indicator of severe HF and early liver cirrhosis, the fECV values using routine multiphasic contrast-enhanced liver CT could be used as a complementary, noninvasive tool for the estimationof HF.