Assessing Liver Function by T1 Maps on Gd-EOB-DTPA- Enhanced MRI for up to 50 Min in Rat Models of Liver Fibrosis: A Longer Hepatobiliary Time Period may Help

摘要

Objectives To investigate whether a longer time period of gadolinium ethoxybenzyl diethylenetriaminepen-taacetic add(Gd-EOB-DTPA)-enhanced T1 mapping scanning,as well as dynamic contrast-enhanced(DCE)and multiple hepatobiliary phase magnetic resonance imaging(MRI)have the potential to provide information about liver function in rats with liver fibrosis.Methods Forty rats were divided into the carbon tetrachloride-induced hepatic injury groups[carbon tetrachloride for four(n=14),eight(n=8),or twelve(n=8)weeks]and the control group(n=10).Gd-EOB-DTPA-enhanced MRI was performed including T1-mapping(delayed to 50 min),DCE,and multiple hepatobiliary phases.Indocyanine green retention rate at 15 min(ICG-R15)was determined.Parameters such as T1 reduction rate(△T1),elimination half-life of △T1(T_(△T1 1/2)),relative enhancement(RE),time to maximum RE(T_(max)),and perfusion parameters were calculated.Pearson correlation analysis was used for correlation analysis between ICG-R15 and each MRI indices.Results △T1 at 30,40,and 50 min showed significant positive correlations with ICG-R15(r=0.784,0.653,0.757,P=0.007,0.041,0.030).T_(△T1 1/2) showed a significant positive correlation with ICG-R15(r=0.685,P=0.029).showed a significant positive correlation with ICG-R15(r=0.532,P=0.019).Conclusions △T1 in the late hepatobiliary phase and T_(△T1 1/2) exhibited moderate correlations with liver function.The longer time period of Gd-EOB-DTPA-enhanced Tl mapping scanning,as well as DCE and multiple hepatobiliary phases,may be of some value for estimating liver function in rats with liver fibrosis.