Which are the cut-off values of 2D-Shear Wave Elastography (2D-SWE) liver stiffness measurements predicting different stages of liver fibrosis, considering Transient Elastography (TE) as the reference method?

Abstract

Introduction: To identify liver stiffness (LS) cut-off values assessed by means of 2D-Shear Wave Elastography (2D-SWE) for predicting different stages of liver fibrosis, considering Transient Elastography (TE) as the reference method.

Methods: Our prospective study included 383 consecutive subjects, with or without hepatopathies, in which LS was evaluated by means of TE and 2D-SWE. To discriminate between various stages of fibrosis by TE we used the following LS cut-offs (kPa): F1-6, F2-7.2, F3-9.6 and F4-14.5.

Results: The rate of reliable LS measurements was similar for TE and 2D-SWE: 73.9% vs. 79.9%, p=0.06. Older age and higher BMI were associated for both TE and 2D-SWE with the impossibility to obtain reliable LS measurements. Reliable LS measurements by both elastographic methods were obtained in 65.2% of patients. A significant correlation was found between TE and 2D-SWE measurements (r=0.68). The best LS cut-off values assessed by 2D-SWE for predicting different stages of liver fibrosis were: F≥1: >7.1 kPa (AUROC=0.825); F≥2: >7.8 kPa (AUROC=0.859); F≥3: >8 kPa (AUROC=0.897) and for F=4: >11.5 kPa (AUROC=0.914).

Conclusions: 2D-SWE is a reliable method for the non-invasive evaluation of liver fibrosis, considering TE as the reference method. The accuracy of 2D-SWE measurements increased with the severity of liver fibrosis.

Keywords: Liver fibrosis; Liver stiffness; Shear Waves Elastography; Transient Elastography.