The clinical value of hepatic extracellular volume fraction using routine multiphasic contrast-enhanced liver CT for staging liver fibrosis

Abstract

To investigate the value of hepatic extracellular volume fractions (fECVs) measured using routine liver computed tomography (CT) evaluating liver fibrosis (LF). A total of 60 patients (male:female ratio, 39:21; mean age, 42.4 years) histologically diagnosed with LF underwent routine liver CT. Absolute enhancement (in Hounsfield units) of the liver parenchyma (Eliver) and aorta (Eaorta) 3 minutes after contrast medium administration was calculated using precontrast and equilibrium phase scans. The fECV was calculated using the following equation: fECV (%)=Eliver× (100 - haematocrit [%])/Eaorta. Correlation between fECV and LF stage was evaluated using the Spearman correlation coefficient. The fECVs were compared between each stage of LF. The diagnostic performance of fECV was assessed using receiver operating characteristic (ROC) curve analysis. The difference among the groups was statistically significant (p<0.05). The fECVs were significantly different (p<0.05) between F0 versus F4, F1 versus F4, and F2 versus F4. The fECVs showed a significant correlation with pathological LF staging (r=0.468, p=0.001). The sensitivity and specificity were 0.76 and 0.68 for severe LF (F≥3); and 0.89 and 0.63 for cirrhosis (F=4). The areas under the ROC curve (AUCs) for F≥3 and F=4 were 0.757 and 0.775, respectively. Calculation of fECV during routine contrast-enhanced liver CT may provide a non-invasive means of assessing LF.