Application of transient elastography in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Although it has become one of the leading causes of cirrhosis and hepatocellular carcinoma in the Western world, the proportion of NAFLD patients developing these complications is rather small. Therefore, current guidelines recommend noninvasive tests for the initial assessment of NAFLD. Among the available non-invasive tests, transient elastography by FibroScar (R) (Echosens, Paris, France) is commonly used by hepatologists in Europe and Asia, and the machine has been introduced to the United States in 2013 with rapid adoption. Transient elastography measures liver stiffness and the controlled attenuation parameter simultaneously and can serve as a one-stop examination for both liver steatosis and fibrosis. Liver stiffness measurement also correlates with clinical outcomes and can be used to select patients for varices screening. Although obesity is a common reason for measurement failures, the development of the XL probe allows successful measurements in the majority of obese patients. This article reviews the performance and limitations of transient elastography in NAFLD and highlights its clinical applications. We also discuss the reliability criteria for transient elastography examination and factors associated with false-positive liver stiffness measurements.