Gd-EOB-DTPA-enhanced MRI T1 mapping for assessment of liver function in rabbit fibrosis model: comparison of hepatobiliary phase images obtained at 10 and 20 min

Objectives To compare hepatobiliary phase (HBP) images obtained at 10 and 20 min after Gd-EOB-DTPA-enhanced MRI for assessment of liver function in rabbit fibrosis model on 3.0 T MR imaging. Methods 34 animals were separated into three groups: 5 for a control group, 14 for a mild fibrosis group, and 15 for a severe fibrosis group based on pathological proof. T1 relaxation times (T1rt) were measured on T1 mapping and reduction rates of T1rt (rrT1rt) were calculated. HBP images were obtained at 10 and 20 min after Gd-EOB-DTPA enhancement. Indocyanine green retention rates at 15 min (ICG R15) were performed for all animals. Results T1rt on pre-enhancement imaging showed no significant difference ( p > 0.05) among all groups. T1rt on 10 min HBP and 20 min HBP showed significant difference ( p < 0.05) among all groups. T1rt and rrT1rt in three groups showed no-significant difference ( p > 0.05) between 10 min HBP and 20 min HBP. T1rt on both 10 and 20 min HBP showed significant correlation with ICG R15 ( p < 0.05); rrT1rt on both 10 min HBP and 20 min HBP showed significant inverse correlation with ICG R15 ( p < 0.05). Conclusions Comparing 10 min HBP and 20 min HBP T1 mapping after Gd-EOB-DTPA enhancement, our results suggest that 10 min HBP T1 mapping is feasible for quantitatively assessing liver function.