LA STIFFNESS EPATICA NELLE MALATTIE EPATICHE CRONICHE: NUOVI SCENARI A CONFRONTO

Abstract Background and aim. Liver stiffness (LS) measured by transient elastography (TE) accurately predicts severity of chronic liver disease (CLD). Point quantification shear-wave elastography (ElastPQ®- pSWE) is a newly developed technique to measure LS incorporated into a conventional ultrasound system. We evaluated feasibility, reproducibility and diagnostic accuracy of both techniques in consecutively recruited CLD patients who concomitantly underwent a liver biopsy. Methods. Over a two-year period, 186 CLD `patients (116 males, 53 years, 132 viral hepatitis ) consecutively underwent ElastPQ®-pSWE (10 valid measurements) blindly performed by two raters whereas TE was performed by one single operator. Interobserver agreement for ElastPQ®-pSWE was analyzed by intraclass correlation coefficient (ICC) and correlated with histological liver fibrosis by METAVIR. Main determinants of ElastPQ®-pSWE were investigated by a linear regression model. Results. 372 (100%) reliable measurements were obtained by ElastPQ®-pSWE and 184 by TE (2 failures, 99%). LS was 8.1±4.5 kPa for by ElastPQ®-pSWE with the first rater and 8.0±4.2 with the second one vs 8.8±3.6 kPa by TE. Overall, ElastPQ®-pSWE ICC was 0.89 (95%CI 0.85-0.91) that was not influenced by age, sex, BMI or liver enzymes. However, ICC increased with time , 1st year 0.86, 95% CI 0.81-0.90 vs second year 92, 95%CI 0.87-0.95. Liver fibrosis was the only independent determinant of LS on ElastPQ®-pSWE. AUROCs for diagnosing F≥2, F≥3 and F=4 were 0.77, 0.85 and 0.88 for ElastPQ®-pSWE vs 0.81, 0.88 and 0.94 for TE. However the ElastPQ®-pSWE AUCROCs after one year of training were 0.86, 0.94 and 0.91. Conclusions. pSWE-ElastPQ reliably and reproducibly evaluates LS, matching for accuracy TE after a learning curve of one year.