[Diagnostic value of gadobenate dimeglumine enhanced MRI in hepatic fibrosis of rats].

Objective: To evaluate the value of Gd-BOPTA enhanced MRI in the staging of liver fibrosis. Method: Fifty male SD rats (6-week-old, 180-220 g) were divided into the modeling group (n=42) and the control group (n=8). The model of liver fibrosis in the modeling group was established by carbon tetrachloride (animal license No. SYXK (Su) 2017-0043). From week 2 to week 10, rats in the modeling group (n=4) and control group (n=1) were randomly selected to scan 1 h(RER1), 2 h(RER2) and 3 h(RER3) after injection of Gd-BOPTA, respectively, to measure the relative enhancement rate (RER) of liver parenchyma. The shape of intrahepatic bile duct and the degree of enhancement at each time point were observed. Results: Forty-two rats (34 rats in the modeling group and 8 rats in the control group) completed the experiment. RER1, RER2 and RER3 of the control group were 1.44±0.37, 1.22±0.37 and 0.84±0.28 respectively. RER1, RER2 and RER3 of the modeling group were respectively: S1 (n=6): 1.49±0.48, 1.29±0.39, 0.91±0.38;S2 (n=9): 1.48±0.44, 1.34±0.37, 1.04±0.40;S3 (n=11): 1.49±0.43, 1.37±0.39, 1.21±0.30; S4 (n=8): 1.49±0.44, 1.40±0.37, 1.24±0.40. There was no significant difference in RER1 and RER2 values between the control group and the liver fibrosis group (F=0.022, P=0.999; F=0.301, P=0.875). There were significant differences between the control group and RER3 values of hepatic fibrosis stage S3 and S4 (t=2.249, P=0.031; t=2.274, P=0.029), there was no significant difference between the remaining groups (all P>0.05).In the control group, the intrahepatic bile duct was obviously strengthened within 1 hour after enhancement, and walked naturally. The intrahepatic bile duct was slightly enhanced 1h after the enhancement of S3-S4 stage of hepatic fibrosis, and the intrahepatic bile duct was significantly enhanced 2-3 hours later, with distorted alignment. Conclusion: Delayed 3 hours liver parenchymal RER and intrahepatic bile duct distortion delay enhancement after Gd-BOPTA enhancement contribute to the S3-S4 diagnosis of liver fibrosis.