Non Alcoholic Steatohepatitis (NASH)

15 year old male obese boy came with pain in abdomen with elevated liver enzymes. He is non alcoholic, not taking any medication and tests negetive for hepatitis. MRI abdomen T1 weighted image shows diffuse fatty infilteration in the liver which is confirmed by loss of signal on ooposed phase chemical shifgt image. Findings are consistent with Non Alcoholic Steatohepatitis (NASH).

Synonyms: Hepatic fatty metamorphosis , Hepatic fatty steatosis, NASH

Nonalcoholic steatohepatitis (NASH) is fat in the liver, with inflammation and damage. It resembles alcoholic liver disease, but occurs in people who drink little or no alcohol. The major feature in NASH is fat in the liver, along with inflammation and damage.Patients generally feel well in the early stages and only begin to have symptoms—such as fatigue, weight loss, and weakness—once the disease is more advanced or cirrhosis develops.

We have to differentiate "Fatty liver", NASH and nonalcoholic fatty liver disease (NAFLD). Fat in their liver, but no inflammation or liver damage, a condition called “fatty liver. If fat is suspected based on blood test results or scans of the liver, this problem is called nonalcoholic fatty liver disease (NAFLD). If a liver biopsy is performed in this case, it will show that some people have NASH while others have simple fatty liver. Main causes for the NASH are elevated blood lipids, such as cholesterol and triglycerides, and many have diabetes or pre-diabetes, obesity.

USG shows diffuse increase in echotexture. CT scan will show diffuse decrease in attenuation. MRI shows intracellular fatty infilteration which is diffusely hyperintense on T1 weighted image (in phase image) and shows loss of signal on opposed phase chemical shift image. These MRI findings in patient with elevated liver enzymes suggestive of NASH. Liver biopsy and histopathology are diagnostic.