Focal fat infiltration is common. It is frequently seen as increased echogenicity on ultrasound, decreased density on CT, and increased T1 signal on MR. There is typically a geographic border and no distortion or displacement of vessels. Alcohol abuse is a common cause. Fifty per cent of patients with poorly-controlled diabetes have evidence of fatty liver. Other causes are obesity, hyperlipidemia, malabsorption, corticosteroids, total parenteral nutrition and pregnancy. Fatty liver is a reversible change, and will generally resolve once the cause is addressed. If the hepatic insult is ongoing, cirrhosis may result.