Noninvasive assessment of hepatic fibrosis staging with MR elastography versus T1ρ imaging / 中华放射学杂志

ABSTRACT

Objective To compare the diagnostic values of magnetic resonance elastography (MRE) and T1ρ imaging in staging hepatic fibrosis (HF) in a rabbit model.Methods The institutional animal care and use committee approved all experiments.Sixty healthy rabbits were divided into HF group (n=44) and control group (n=16).Each eight rabbits in the HF group and 4 rabbits in the control group were randomly selected at the 4th,5th,6th week and the remaining rabbits at the 10th week after subcutaneous injection with 0.1 ml 50％ CCl4 oily solution per kilogram of body respectively,to undergo liver MR scan including axial liver MRE and T1ρ imaging.The values of liver stiffness (LS) and T1ρ were measured.Masson trichrome staining of liver tissue was used.According to the Scheuer scoring system,rabbits were classified into F0 to F4 group based on the percentage of hepatic fibrosis.The difference of LS values and Tip values among stage F0 to F4 were compared by the one-way ANOVA analysis.The correlations between pathological staging and LS,T1ρ values were performed by the Spearman correlation analysis.ROC curve analysis was performed to compare the value of MRE with T1ρ imaging.Results Forty three rabbits were included,there were 10,8,8,8,9 rabbits in F0,F1,F2,F3 and F4 stage,respectively.LS values were (1.051±0.155),(1.335±0.235),(1.401±0.163),(2.001±0.499) and (2.981±0.714) kPa in F0,F1,F2,F3 and F4,respectively,while T1 p values were (23.20±4.02),(24.28±2.93),(25.40± 1.82),(24.69± 1.85) and (31.54±3.39) ms (all P＜0.05).The correlation of LS values with hepatic fibrosis staging measured on MRE was stronger than T19 values (r values were 0.916 and 0.608,all P＜0.01).Area under ROC curve of LS value for differentiating hepatic fibrosis stage were 0.938 to 0.989,while the areas of T1ρ were 0.771 to 0.954.Conclusion MR elastography is an accurate technique for quantitatively staging hepatic fibrosis and superior to T1ρ imaging.