The prevalence of steatosis in adults is globally around 20% in western countries. There are many aetiologies and globally we dissociate the steatosis of alcoholic origin and non-alcoholic fatty liver disease (NAFLD). The latter are dominated by the metabolic syndrome. This is defined by the association of abdominal obesity with one of the following criteria: type II diabetes, hypercholesterolemia, hypertriglyceridaemia, or arterial hypertension. Hyperferritinemia may be a sign of inflammation but also of a freely associated liver iron overload. This syndrome recognized by WHO is relatively frequent, and its prevalence increases with age. It predisposes to the occurrence of type 2 diabetes and cardiovascular accidents.
In addition, due to unclear co-factors, more than 10% of NAFLDs will be accompanied by hepatocellular lesions, chronic inflammation and fibrosis and are referred to as non-alcoholic steatohepatitis (NASH). The latter would be responsible for a large proportion of cryptogenetic cirrhoses. In addition to the specific risk of steatosis to fibrosing liver disease, steatosis is considered a risk factor when associated with hepatopathy such as viral hepatitis.
There is a major challenge to better understand the factors that make a NAFLD evolve into a NASH. Iron would play a role. The analysis of the unsaturated / saturated fatty acids ratio was also advanced. These two points encourage the development of techniques for MRI analysis of the fat composition of the hepatic parenchyma.