Ultrasound Shearwave (SW) speed measurements using Transient Elastography (TE) is an accepted non-invasive test of liver stiffness and indirectly the presence of significant liver fibrosis. Newer SW technologies have since been developed but have yet to be validated against this standard of care test.To assess the reliability and accuracy of 2D Ultrasound SW technology at grading the severity of Liver Fibrosis using TE as the gold standard.
METHOD AND MATERIALSCenters from France, Germany, Italy and United Kingdom were involved. Patients were recruited prospectively with a variety of chronic liver diseases to have 2D Ultrasound Shearwave (ToSWE) (Toshiba Medical Systems) and TE (Echosens) performed on the same day.10 valid measurements were obtained from fasted patients (>8 hours) using both techniques and the median result in kPa was used for analysis. Based on a previous meta-analysis (Tsochatzis, et al. J Hepatol 2011) for staging liver fibrosis (F), TE cut-offs of 7.0, 9.5 and 12.0 kPa, were used to denote liver fibrosis stages of significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4) respectively. A TE value of < 7.0 kPa was used to denote no significant fibrosis (F0/F1). The measurements obtained from ToSWE were correlated with the TE-derived stages of fibrosis.
RESULTS367 patients have been recruited to date, (215 M:152 F) with a mean age of 53 years (range: 21-88 years). The main etiologies of liver disease were HCV-related (64%) and HBV-related (23%). The rest comprised a mixture of ALD, AIH and NAFLD.350 datasets were complete showing excellent correlation of liver stiffness values between the ToSWE and TE techniques at all centres (R2 correlation range: 0.78-0.92). The mean elasticity values using ToSWE for each liver fibrosis stage as described above was: F0/F1 (n= 179: 6.0 ± 1.4 kPa), F2 (n = 54: 7.0 ± 3.0 kPa), F3 (n = 42: 9.2 ± 2.2 kPa) and F4 (n = 75: 16.7 ± 11.8 kPa). This was highly statistically significant between all groups (Mann Whitney U test: p<0.001 for all pairs).
CONCLUSIONThe liver stiffness measurements using ToSWE correlates well with TE and can be used to distinguish patients with significant liver fibrosis non-invasively in the appropriate clinical setting.
CLINICAL RELEVANCE/APPLICATION2D Shearwave elastography is a useful non-invasive tool for grading the severity of chronic liver disease and can be linked with current established treatment algorithms for TE.