How does fatty liver appear on an ultrasound?

Fatty liver, or hepatic steatosis, is characterized by the accumulation of fat within liver cells, which alters the liver's echogenicity seen on ultrasound. When fatty liver is present, the liver typically appears more echogenic, or brighter, than the surrounding structures, such as the kidney. This increased echogenicity occurs because the fat within the liver cells reflects ultrasound waves more effectively than the normal liver tissue, leading to a bright appearance on the ultrasound image.

In contrast, decreased echogenicity would suggest conditions like liver cirrhosis or acute liver failure, where the liver may appear darker than normal or have a complicated echogenic pattern. A normal echogenic pattern would imply that there is no fat accumulation or pathology affecting the liver. The description of a hypoechoic liver with bright margins would also not accurately describe fatty liver, as this pattern might indicate other forms of liver pathology rather than fatty accumulation.

Therefore, the identification of increased echogenicity of the liver compared to the kidney is a key sonographic feature that indicates the presence of fatty liver disease. This distinction is essential for radiologists and sonographers when interpreting ultrasound images for liver conditions.