Comparing 2D-shear wave to transient elastography for the evaluation of liver fibrosis in nonalcoholic fatty liver disease.

Abstract

The aim of this study is to evaluate the performance of 2D-shear wave elastography (2D-SWE) in patients with nonalcoholic fatty liver disease (NAFLD) and compare it to transient elastography. Over 6 months, 552 patients with NAFLD underwent liver stiffness measurement (LSM) by both 2D-SWE and transient elastography with controlled attenuation parameter (CAP) at the same visit. LSM was not feasible by transient elastography (M/XL probe) in 18 (3.3%) and by 2D-SWE in 26 (4.7%) patients. The median LSM of transient elastography was 5.5 (2.8-75) kPa and of 2D-SWE 6.2 (3.7-46.2) kPa. LSMs by transient elastography and 2D-SWE were correlated regardless of the obesity status (r, 0.774; P < 0.001; r, 0.774; P < 0.001; r, 0.75; P < 0.001 in BMI <25, 25-30 and ≥30 kg/m2 respectively), or the degree of liver steatosis (r = 0.63; P < 0.001 and r = 0.743; P < 0.001 in mild and moderate/severe steatosis, respectively). According to transient elastography, 88 (15.9%) patients were classified with at least severe fibrosis (≥F3) and 55 (10%) with cirrhosis. By using the 2D-SWE, 85 (15.4%) patients had at least severe fibrosis and 52 (9.4%) cirrhosis. The correlation between the two methods was strong in patients with at least severe fibrosis (r, 0.84; P < 0.001) or cirrhosis (r, 0.658; P < 0.001). When transient elastography was used as reference, 2D-SWE showed an excellent accuracy of 98.8 and 99.8% in diagnosing severe fibrosis and cirrhosis, respectively. In NAFLD, 2D-SWE and transient elastography have comparable feasibility and clinical applicability providing LSMs with strong correlation, even in overweight/obese patients, independently of the severity of liver steatosis and fibrosis. Thus, either of the two methods can be effectively used for the assessment of fibrosis in this setting.