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

Abstract

Background and aim 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. Methods 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. Results 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/m 2 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. Conclusions 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.