A Large Scale Validation of Two-Dimensional Shear Wave Elastography in the Diagnosis of Liver Fibrosis Progression in Patients with Chronic Hepatitis B

Abstract

Two-dimensional shear wave elastography (2D-SWE) is a noninvasive approach for staging chronic liver diseases. Our previous published study had established the cut-off value of 2D-SWE in the diagnosis of significant fibrosis (7.2 kPa), severe fibrosis (9.2 kPa), and cirrhosis (10.4 kPa) based on 304 patients with chronic hepatitis B (CHB). The aim of this study is to validate the value of 2D-SWE in assessing liver fibrosis progression and to compare its diagnostic accuracy with serological fibrosis indices involving aminotransferase/platelet ratio index (APRI), fibrosis index based on the 4 factors (FIB-4), King’s score and Forns index. From July 2015 to January 2017, 639 subjects who underwent partial hepatectomy were enrolled in the study and they were divided into S0–S4 groups by using resected liver specimen. There were 535 males and 104 females with an average age 54.1±10.7 yrs (19-82 yrs). All patients were examined with 2D-SWE (Aixplorer ultrasound system) and serological testing preoperatively to obtain liver stiffness measurements (LSMs) and values of serum fibrosis models. Performance of noninvasive methods was analyzed for validation with areas under the receiver operating characteristic curve (AUCs). Intraobserver agreement of intraclass correlation coefficient was 0.943 for the five measurements of liver stiffness. Mean values of LSMs were 5.52±1.15 kPa (n=33), 6.51±1.09 kPa (n=74), 7.95±0.81 kPa (n=107), 9.41±1.32 kPa (n=135), and 14.55±3.50 kPa (n=290) for the fibrosis S0, S1, S2, S3, and S4 groups, respectively. When the optimal cutoff values of 2D-SWE were applied for S2-4 fibrosis stages, AUCs in predicting significant fibrosis, severe fibrosis and cirrhosis were 0.970, 0.971 and 0.979, respectively. All noninvasive approaches were statistically significantly related to hepatic fibrosis stage (P<0.05). When compared with four serological fibrosis indices, 2D-SWE showed significantly higher AUCs than four serum fibrosis indices in predicting significant fibrosis, severe fibrosis and cirrhosis (P < 0.05 for all). The large scale validation shows that 2D-SWE is an effective approach in predicting significant fibrosis, severe fibrosis, and cirrhosis in CHB patients with notably higher diagnostic accuracy than serum fibrosis models.