Comparison of the clinical usefulness of shear wave elastography relative to transient elastography and other markers of liver fibrosis

Abstract

Background and Aim: Shear wave elastography (SWE) is an emerging ultrasound-related technology for the assessment of liverfibrosis. Liverfibrosis is the harbinger of many liver-related complications in patients with chronic liver disease but is often difficult to quantify non-invasively. The usefulness and reliability ofSWEare unclear relative to other markers of liver fibrosis. We aimed to compare the clinical usefulness of SWE relative to transient elastography (TE), liver ultrasound, and other standard biochemical markers of chronic liver disease in patients with varied liver disorders. Methods: SWE assessment was performed using a Toshiba Aplio 500 or Canon Aplio i800 machine, concurrently with liver ultrasound, on 421 serial adult patients at a tertiary hospital. Among these patients, 227 also had liver TE. Patient age, sex, body mass index (BMI), alcohol history, liver disease diagnosis, and laboratory results were recorded. Associations between SWE, TE, and patient factors were sought. Suspected significant liver fibrosis was defined by a liver stiffness measurement (LSM) interpretation of ≥ F2 equivalent using Metavir staging. TE was considered as the reference. Sonographers were blinded to the TE results. Results: Patients were predominantly male (67.5%). Men and women were matched in terms of age and BMI. The indications for SWE included nonalcoholic fatty liver disease (NAFLD) (10%), chronic hepatitis B (22%), chronic hepatitis C (38%), alcohol-related liver disease (18%), and others (12%). The mean ± SD age was 53 ± 14 years, BMI was 27.7 ± 6.3 kg/m2, ultrasound-measured skin to liver capsule distance was 20.0 ± 7.3 mm, serum alanine aminotransferase (ALT) level was 39 ± 27 U/L, and aspartate aminotransferase (AST) was 48 ± 32 U/L. The median liver stiffness was 9.9 kPa (IQR, 6.4-20.0) with SWE and 9.2 kPa (IQR, 5.8- 20.9) with TE. Patients with suspected significant liver fibrosis determined by SWE, compared with patients not suspected of having significant fibrosis, were significantly older and had higher BMI, skin to liver capsule distance, TE LSM, alcohol consumption, and the blood-based assessments of AST (but not ALT), AST/ALT ratio, AST to platelet ratio index (APRI), Fibrosis-4 index (FIB-4), Hepascore, and NAFLD Fibrosis Score (NFS), but lower platelet count and serum albumin level (P < 0.05 for all). There was a strong correlation between SWE and TE LSM (r = 0.77, P < 0.001). The strength of correlation between SWE and TE varied by etiology of liver disease: alcohol (r = 0.6, P = 0.005), hepatitis B (r = 0.5, P < 0.001), hepatitis C (r = 0.73, P < 0.001), and NAFLD (r = 0.87, P < 0.001). Using multiple logistic regression analysis, independent predictors of significant liver fibrosis using either SWE or TE were FIB-4, BMI, and male sex (after adjusting for other covariates). Conclusion: SWE was found to be a useful test for suspected liver fibrosis in various liver disorders, and results were found to correlate with TE LSM plus clinically relevant anthropometric and laboratory parameters in the studied population.