Correlation Between QElaXto Techniques and Supersonic Imagine for Liver Stiffness Quantification in Chronic Liver Disease

OBJECTIVES Intersystem variability in liver stiffness (LS) quantification with ultrasound shear wave elastography (SWE) precludes direct comparison of results obtained with different equipment. The aim of this study was to investigate the agreement between point-SWE and 2-dimensional-SWE with Esaote-MyLab 9 (p-QElaXto and 2D-QElaXto, respectively) and 2D-SWE with SuperSonic Imagine (SSI) in order to assess specific LS thresholds for fibrosis staging with QElaXto techniques, using SSI as a reference standard. METHODS A total of 235 compensated chronic liver disease (CLD) patients without comorbidities potentially affecting LS were enrolled in the study. Among them, 101 patients underwent also liver biopsy. Agreement between the equipment was assessed with Pearson coefficient and Bland-Altman analysis, while cut-off values were calculated with receiver operating characteristics analysis. RESULTS Correlation between 2D-QElaXto and p-QElaXto with SSI resulted very good (r = 0.898 and r = 0.866), especially in precirrhotic stages, with a mean difference between LS values of -1.3 kPa for 2D-QElaXto and -0.6 kPa for p-QElaXto compared with SSI. Cut-off thresholds for diagnosing fibrosis ≥F2, ≥F3, and F4 in non-HBV-related CLD were, respectively, 5.5, 8.0, and 10.6 kPa for 2D-QElaXto and 6.1, 8.1, and 11.7 kPa for p-QElaXto. All three SWE techniques were effective in differentiating significant fibrosis ≥F2 from mild or absent fibrosis in the subgroup of patients submitted to biopsy and showed good feasibility. CONCLUSIONS Correlation between QElaXto techniques and SSI in LS measurements is very good. Our study identifies for the first time cut-off thresholds for fibrosis staging in non-HBV-related CLD using two QElaXto techniques.