Staging liver fibrosis on multiparametric MRI in a rabbit model with elastography, susceptibility-weighted imaging and T1ρ imaging: a preliminary study.

Background: Magnetic resonance elastography (MRE), susceptibility-weighted imaging (SWI), and T1ρ are three techniques for staging of liver fibrosis (LF).

Objective: To assess the value of MRE, SWI, and T1ρ imaging in staging LF.

Methods: Sixty rabbits were injected with 50% CCl4oil solution, whereas 20 rabbits were given normal saline. All rabbits underwent pathological examination to determine LF stages. The liver stiffness (LS), liver-to-muscle signal intensity ratio (SIR), and T1ρ values were measured from MRE, SWI, and T1ρ imaging, respectively.

Results: The number of rabbits was 14, 11, 10, 9, and 11 for F0, F1, F2, F3, and F4, respectively. LS (r = 0.91) and T1ρ (r = 0.51) positively correlated with LF stages, while negative correlation was present for SIR (r = -0.81). Among the three parameters, the LS values revealed the best diagnostic efficacy in staging LF, with an AUC value of 0.95 for ≥F1, 0.95 for ≥F2, 0.99 for ≥F3, and 0.98 for ≥F4. The combination of LS and SIR could best predict LF stages ≥F1, ≥F2, ≥F3 and ≥F4, with AUC values of 0.97, 0.98, 0.99, and 0.99, respectively, which were greater than those of the other two-paired parameters. A multiparametric analysis showed that the combination of all three parameters had AUC values of 0.97, 0.98, 1.00, and 1.00 for staging ≥F1, ≥F2, ≥F3, and ≥F4, respectively.

Conclusions: Multiparametric MR imaging was superior to individual imaging for LF staging.