Evaluating the Significance of Viscoelasticity in Diagnosing Early-Stage Liver Fibrosis with Transient Elastography

• Published in: PloS one Vol. 12; no. 1; p. e0170073
• Main Authors: Zhao, Jingxin, Zhai, Fei, Cheng, Jun, He, Qiong, Luo, Jianwen, Yang, Xueping, Shao, Jinhua, Xing, Huichun
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.01.2017; Public Library of Science (PLoS)
• Subjects: Accuracy; Adult; Bile; Biology and Life Sciences; Biomedical engineering; Biopsy; Body mass; Chronic infection; Clinical medicine; Computer simulation; Diagnosis; Diagnostic systems; Early Diagnosis; Elasticity; Elasticity Imaging Techniques - methods; Female; Fibrosis; Finite element method; Hepatitis; Hepatitis B; Hepatitis B virus; Hepatology; Hospitals; Humans; Liver; Liver cirrhosis; Liver Cirrhosis - diagnosis; Liver Cirrhosis - diagnostic imaging; Liver Cirrhosis - pathology; Liver diseases; Liver research; Male; Mathematical models; Medical diagnosis; Medical imaging; Medical technology; Medicine and Health Sciences; Middle Aged; NMR; Nuclear magnetic resonance; Numerical simulations; Physical Sciences; Reliability analysis; ROC Curve; Sensitivity and Specificity; Shear; Stiffness; Two dimensional models; Ultrasonic imaging; Ultrasound; Viral infections; Viscoelasticity; Viscosity; Wave attenuation; Wave propagation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0170073

Transient elastography quantifies the propagation of a mechanically generated shear wave within a soft tissue, which can be used to characterize the elasticity and viscosity parameters of the tissue. The aim of our study was to combine numerical simulation and clinical assessment to define a viscoelastic index of liver tissue to improve the quality of early diagnosis of liver fibrosis. This is clinically relevant, as early fibrosis is reversible. We developed an idealized two-dimensional axisymmetric finite element model of the liver to evaluate the effects of different viscoelastic values on the propagation characteristics of the shear wave. The diagnostic value of the identified viscoelastic index was verified against the clinical data of 99 patients who had undergone biopsy and routine blood tests for staging of liver disease resulting from chronic hepatitis B infection. Liver stiffness measurement (LSM) and the shear wave attenuation fitting coefficient (AFC) were calculated from the ultrasound data obtained by performing transient elastography. Receiver operating curve analysis was used to evaluate the reliability and diagnostic accuracy of LSM and AFC. Compared to LSM, the AFC provided a higher diagnostic accuracy to differentiate early stages of liver fibrosis, namely F1 and F2 stages, with an overall specificity of 81.48%, sensitivity of 83.33% and diagnostic accuracy of 81.82%. AFC was influenced by the level of LSM, ALT. However, there are no correlation between AFC and Age, BMI, TBIL or DBIL. Quantification of the viscoelasticity of liver tissue provides reliable measurement to identify and differentiate early stages of liver fibrosis.