Liver stiffness measurement reliability and main determinants of point shear-wave elastography in patients with chronic liver disease.

BACKGROUND: Liver stiffness (LS) measured by transient elastography (TE) accurately predicts the severity of chronic liver diseases (CLD). Point quantification shear-wave elastography (pSWE) is a new technique incorporated into a conventional ultrasound system for measuring LS. We evaluated pSWE feasibility, reproducibility and diagnostic accuracy in consecutively recruited CLD patients who concomitantly underwent TE and liver biopsy. AIM: To evaluate pSWE feasibility, reproducibility and diagnostic accuracy in consecutively recruited CLD patients who concomitantly underwent TE and liver biopsy. METHODS: Over 2 years 186 CLD patients (116 males, 132 viral hepatitis) consecutively underwent pSWE (10 valid measurements by ElastPQ) blindly performed by two raters. A further operator performed TE. Inter-observer agreement for pSWE was analysed by intraclass correlation coefficient (ICC) and correlated with histological liver fibrosis (METAVIR). Main determinants of pSWE were investigated by linear regression model. RESULTS: Three hundred and seventy-two (100%) reliable measurements were obtained by pSWE and 184 by TE (99%). LS was 8.1 ± 4.5 kPa for pSWE with the first rater and 8.0 ± 4.2 kPa with the second one vs. 8.8 ± 3.6 kPa for TE. pSWE ICC was 0.89 (95% CI 0.85-0.91), not influenced by age, sex, BMI, liver enzymes, liver aetiology. ICC increased over time with year 1 at 0.86 and 95% CI 0.81-0.90 vs. year 2 at 0.92 and 95% CI 0.87-0.95. Liver fibrosis was the only independent determinant of LS on pSWE. The AUROCs for diagnosing F ≥ 2, F ≥ 3 and F = 4 were 0.77, 0.85 and 0.88 for pSWE vs. 0.81, 0.88 and 0.94 for TE. After 1-year training they were 0.86, 0.94 and 0.91. CONCLUSION: Point quantification shear-wave elastography reliably and reproducibly evaluates liver stiffness, matching transient elastography for accuracy after a 1-year learning curve or 130 examinations.

Feasibility and reproducibility of spleen transient elastography and its role in combination with liver transient elastography for predicting the severity of chronic viral hepatitis.

Liver transient elastography (L-TE) is a reliable, noninvasive predictor of disease severity in chronic liver disease of viral aetiology (CLD). Owing to the relationships among severity of CLD, portal hypertension and spleen involvement, the assessment of splenic stiffness (S-TE) may have an added value in staging CLD. Of 132 CLD patients of viral aetiology, 48 with myeloproliferative disorders (MD) and 64 healthy volunteers (HV), were concurrently investigated by both L-TE and S-TE. Liver disease severity was staged by liver biopsy (LB; Metavir) taken concurrently with TE examination and upper gastrointestinal tract endoscopy for gastro-oesophageal varices. The S-TE inter-observer agreement was analysed by an intra-class correlation coefficient (ICC); L-TE and S-TE accuracy was evaluated by receiver operating characteristic (ROC) curve analysis. Logistic regression analysis assessed the independent effect of L-TE and S-TE as predictors of hepatic fibrosis stage. S-TE failed in 22 CLD (16.6%), 12 (25%) MD and 12 (18%) HV. In the three groups, the ICC was 0.89 (0.84-0.92), 0.90 (0.85-0.94) and 0.86(0.80-0.91), respectively. In the CLD group, L-TE and S-TE independently predicted significant fibrosis (OR 5.2 and 4.6) and cirrhosis (OR 7.8 and 9.1), but at variance from L-TE, S-TE was independent from liver necroinflammation and steatosis. The NPV of S-TE for gastro-oesophageal varices was 100% using a 48 kPa cut-off. In CLD, spleen stiffness alone or in combination with hepatic stiffness can be reliably and reproducibly assessed by TE with the added value of improving the noninvasive diagnosis of severe liver disease and excluding the presence of oesophageal varices.