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

Shear wave elastography (SWE) is an emerging ultrasound-related technology for assessment of liver fibrosis. The usefulness and reliability of SWE is unclear relative to other markers of liver fibrosis. We compared 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. SWE assessment was performed using a Toshiba Aplio 500 or Canon Aplio i800 machine, concurrently with liver ultrasound on 421 adult patients. Amongst these patients 227 also had liver transient elastography (TE). Patient age, gender, 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 liver stiffness measurement interpretation of ≥ F2 equivalent using Metavir staging. Patients were predominantly male (67.5%). Males and females were matched as regards age and BMI. The indications for SWE included nonalcoholic fatty liver disease (10%), chronic hepatitis B (22%), chronic hepatitis C (38%), alcohol-related liver disease (18%) and others (12%). 23%The mean (standard deviation) age was 53 (14) years, body mass index 27.7 (6.3) kg/m2, ultrasound-measured skin to liver capsule distance 20.0 (7.3)mm, serum ALT 39(27) U/L and AST 48(32) U/L. The median (IQR) liver stiffness was 9.9 (6.4-20.0) kPa with SWE and 9.2 (5.8-20.9) kPa with TE. Patients with suspected significant liver fibrosis determined by SWE, compared with patients not suspected of having significant fibrosis, were significantly older, had higher BMI, skin to liver capsule distance, TE liver stiffness measurement, alcohol consumption, and blood based assessments 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 (p < 0.05 for all). There was a strong correlation between SWE and TE liver stiffness measurement (r = 0.77, p < 001). The strength of correlation between SWE and TE varied by aetiology 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), 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). SWE was found to be a useful test for suspected liver fibrosis in various liver disorders, and results were found to correlate with TE liver stiffness measurement plus clinically relevant anthropometric and laboratory parameters. [ABSTRACT FROM AUTHOR]