Liver Steatosis and NAFLD

Liver steatosis is the hallmark of non-alcoholic fatty liver disease (NAFLD), the most frequent chronic liver disease in the western countries. NAFLD ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) and cirrhosis. Steatosis is also common in other diffuse liver diseases. Regardless the etiology, liver fat accumulation induces liver damage, being associated with poor outcomes of chronic liver diseases. Liver biopsy is the gold standard for diagnosis and stratification of NAFLD, and also for distinguishing simple steatosis from NASH and staging fibrosis. However, liver biopsy is invasive and subject to substantial variability. Therefore, over the last years, the global burden of NALFD and the potential clinical impact of early detection and monitoring of hepatic steatosis has fostered the use of non-invasive imaging modalities for the assessment of steatosis and the search for imaging biomarkers of fat. In this chapter, we will review the role of different imaging modalities in the detection and quantification of liver steatosis, highlighting the role of imaging biomarkers of steatosis.