Quantitative evaluation of liver function by liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI

Abstract

Objective To investigate the utilization of liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI for liver function evaluation.Methods Fifty-five patients who received enhanced MRI with Gd-EOB-DTPA were retrospectively analyzed.Images were obtained before injection and in hepatobiliary phase (5,10,and 20 minutes after Gd-EOB-DTPA injection).The patients were assigned into two subgroups according to individual liver function (n =35 in Group 1:normal liver and Child-Pugh class A; n =20 in Group 2:Child-Pugh class B and C).The relative liver enhancement (RE) was calculated at different time point.The general data (age,sex) and relevant laboratory results were recorded.Independent sample t-test was conducted to compare the RE between two groups at different time point.ROC curve was used to determine the best time point and RE threshold that can reflect the differences between two groups.Univariate analyses was performed to analyze the relationship between RE at the best time point and laboratory results.Multivariate analyses was performed to screen the independent influencing factor for RE at the best time point.Results The differences of RE between two groups were statistically significant at all time points (P ＜ 0.0001).10 minutes was the best time point for detecting the differences of liver function between two groups.When an RE cutoff value (＞ 1.52) was applied,normal or Child-Pugh class A could be predicted with sensitivity of 74.3％ and specificity of 90％.RE at the best time point was significantly related with total serum bilirubin level (TBil),serum albumin level (Alb) and prothrombin time (PT).And TBil was an independent influencing factor.Conclusion RE can be used to evaluate the liver function,and 10 minutes is the best time point that can be used to differentiate patients with normal or mild liver damage from those with moderate or severe liver damage. Key words: Liver function; Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) ; Magnetic resonance imaging (MRI)