Advances in noninvasive methods for diagnosing nonalcoholic fatty liver disease.

The prevalence of nonalcoholic fatty liver disease (NAFLD), one of the most common chronic liver diseases worldwide, has been increasing. In terms of pathological changes, NAFLD can be divided into simple steatosis, nonalcoholic steatohepatitis (NASH) and liver cirrhosis. Hepatocyte damage and inflammatory activity are the main characteristics for evaluating the progress of liver disease. Early and effective diagnosis of the disease is quite important. Pathological findings based on liver biopsy or resected specimens are considered the gold standard for diagnosing and staging steatosis, fibrosis and cirrhosis; however, it is invasive and may lead to related complications. Non-imaging methods such as clinical features and biochemical tests, and imaging methods such as ultrasonography, FibroScan, computed tomography and magnetic resonance imaging are the commonly used noninvasive alternatives, being relatively novel, safe and reliable. In this review, we summarized the benefits and shortcomings of these non-invasive methods for the evaluation of NAFLD.