MR elastography on 3.0 T scanner: a preliminary study of liver stiffness measurements and interrater consistency In volunteers and patients with chronic liver disease

Objective: To estimate reliability of magnetic resonance elastography (MRE) in measuring liver stiffness of volunteers and patients with chronic liver disease and to assess inter-rater consistency. Methods: MRE was performed on a 3.0 T scanner in all subjects, including 24 volunteers (control group) and 64 patients with liver disease (chronic liver disease group), liver stiffness was measured blindly by two raters. The pathological fibrosis score was applied as a standard reference for liver fibrosis in 22 patients. The intraclass correlation coefficient (ICC) was used to evaluate inter-rater reliability. The differences of liver stiffness between two groups were evaluated using non-parametric Mann-Whitney U test. Spearman analysis was used to analyze the correlation between fibrosis stages and liver stiffness. Results: The intraclass correlation coefficient of liver stiffness was perfect (ICC =0.99, P < 0.01) between two raters. There was significant difference of mean stiffness between control group and patient group (U = 90.5, P <0.01) with (2.35 ± 0.34) kPa and (4.17 ± 0.47) kPa, respectively. The correlation between fibrosis stage (3, 3, 5, 5 and 6 patients in fibrosis stage SO, S1, S2, S3 and S4) and stiffness (2.13, 3.25, 3.82, 5.45 and 7.35 kPa) was very strong (r = 0.96, P < 0.01). Conclusion: MRE is a reliable and promising tool to measure liver stiffness and to assess liver fibrosis. (authors)