Correlation between a New Point-Shear Wave Elastography Device (X+pSWE) with Liver Histology and 2D-SWE (SSI) for Liver Stiffness Quantification in Chronic Liver Disease

Background: The aim of this study was to investigate the feasibility, the correlation with previously validated 2D-SWE by supersonic imagine (SSI), and the accuracy in fibrosis-staging of a novel point shear-wave elastography device (X+pSWE) in patients with chronic liver disease. Methods: This prospective study included 253 patients with chronic liver diseases, without comorbidities potentially affecting liver stiffness. All patients underwent X+pSWE and 2D-SWE with SSI. Among them 122 patients also underwent liver biopsy and were classified according to histologic fibrosis. Agreement between the equipment was assessed with Pearson coefficient and Bland-Altman analysis, while receiver operator characteristic curve (ROC) analysis with Youden index was used to establish thresholds for fibrosis staging. Results: A very good correlation was found between X+pSWE and 2D-SWE with SSI (r2 = 0.94; p < 0.001), with X+pSWE average liver stiffness values 0.24 kPa lower than those obtained with SSI. AUROC of X+pSWE for the staging of significant fibrosis (F2), severe fibrosis (F3) and cirrhosis (F4) using SSI as a reference standard was 0.96 (95% CI, 0.93-0.99), 0.98 (95% CI, 0.97-1) and 0.99 (95% CI, 0.98-1), respectively. The best cut-off values for diagnosing fibrosis ≥F2, ≥F3 and F4 were, respectively, 6.9, 8.5 and 12 for X+pSWE. According to histologic classification, X+pSWE correctly identified 93 out of 113 patients (82%) for F ≥ 2 and 101 out of 113 patients (89%) for F ≥ 3 using the aforementioned cut-off values. Conclusion: X+pSWE is a useful novel non-invasive technique for staging liver fibrosis in patients with chronic liver disease.