Diagnostic value of optimised real-time sonoelastography in the assessment of liver fibrosis in chronic hepatitis B and C

AIM To optimise the method of real-time elastography (RTE) in the assessment of liver fibrosis using an in-house prepared method for elastogram analysis, as well as a semiquantitative analysis based on newly introduced parameters. MATERIAL AND METHODS Sonoelastography was performed in 94 patients with various degrees of liver fibrosis and also in 25 healthy volunteers. As a reference method for diagnostic efficacy of sonoelastography-based parameters used for the assessment of fibrosis degree in patients with chronic B and C hepatitis, a liver biopsy was used. Patient's elastograms were analysed using in-house prepared software, Pixel Count, calculating two semiquantitative parameters: mean stiffness fraction (MSF%) and intrinsic stiffness ratio (ISR). RESULTS Statistically significant differences between distributions of the above presented parameters for different degrees of liver fibrosis were revealed. Indices of diagnostic efficacy for detection of significant liver fibrosis (F ≥ 2) using MSF% amounted to: sensitivity - 76%, specificity - 87% and ISR: 81% and 87%, respectively. Sensitivity of both parameters in detection of cirrhosis (F = 4) was equal to 88% and specificity amounted to: for MSF% - 84% and ISR - 86%. Interobserver reproducibility determined for both of the above parameters was high, intraclass correlation coefficients (ICC) were 0.91 for MSF% and 0.93 for ISR. CONCLUSIONS Real-time elastography applied in this study, using in-house prepared Pixel Count software, provided good reproducibility and diagnostic efficacy, especially specificity, in the assessment of liver fibrosis degree.