Hepatic Steatosis Part 1: Pathophysiology

Audience: Radiologist, Residents and Fellows
Learning Objectives: Describe the pathophysiology of hepatic steatosis
Non-alcoholic steatohepatitis and cirrhosis
Alcoholic steatohepatitis
Transient steatosis

Clearance of lipid from systemic circulation in the setting of hyperlipidemia
De novo lipogenesis to decrease systemic hyperglycemia
Clearance of consumed carbohydrates and fat from portal circulation
Impaired beta-oxidation and ketogenesis, which is required for lipid processing
Excess triglyceride accumulation within hepatocytes results in…
“Ballooning” of cells
Cytoplasmic free fatty acids which cause oxidative stress
Release of pro-inflammatory signals
Macrophages, neutrophils, NK cells and lymphocytes are recruited

Summary:
Hepatic steatosis is very common condition in patients who undergo medical imaging
Steatosis can be diagnosed on US, CT or MRI
Accumulation of intracellular lipid can lead to inflammation, non-alcoholic fatty liver disease and cirrhosis
Multiple etiologies can cause steatosis including alcohol use, obesity, diabetes, steroids, and chemotherapy

White blood cells activate hepatic stellate cells that result in fibrosis