Evaluation of the Liver Fibrosis Index calculated by using real-time tissue elastography for the non-invasive assessment of liver fibrosis in chronic liver diseases

Aim A rapid and non-invasive method of detecting fibrosis in patients with chronic liver diseases is of major clinical interest. The purpose of this study was to comparatively investigate the effectiveness of the Liver Fibrosis Index (LF Index) calculated using real-time tissue elastography (RTE) in patients with non-alcoholic fatty liver disease (NAFLD) and patients with chronic hepatitis C (CHC). Methods Twenty-seven patients with biopsy-proven NAFLD and 93 patients with biopsy-proven CHC were included. They underwent transient elastography (TE), serum liver fibrosis marker testing and RTE to calculate the LF Index. Results The LF Index showed a stepwise increase with increasing histological severity of fibrosis in CHC patients (P = 0.0102), whereas no significant correlation of the LF Index with the histological severity of liver fibrosis in NAFLD patients (P = 0.852). There was a significant correlation between the LF Index and liver stiffness measured by TE in CHC patients (r = 0.319, P = 0.0009). On the other hand, no such correlation was observed in NAFLD patients. While in CHC patients, the LF Index was correlated with the FIB-4 index, no such correlation was observed in NAFLD patients. Conclusion The LF Index calculated by RTE is effective for assessment of liver fibrosis in patients with CHC. On the other hand, it is not useful in patients with NAFLD. This is the first study to compare the clinical usefulness of RTE as non-invasive assessment of liver fibrosis between CHC and NAFLD. Further investigations are required to refine statistical assessment of RTE.