KEY FACTS
Terminology
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Accumulation of triglycerides within hepatocytes
Imaging
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Diffuse hepatic steatosis
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Increased echogenicity: Liver more echogenic than kidney
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Attenuation of US beam results in poor visualization of diaphragm
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Blurry margins or poorly visualized hepatic and portal veins
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Focal hepatic steatosis
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Geographic hyperechoic area or multiple confluent hyperechoic lesions
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No mass effect with vessels running undisplaced through lesion
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Wedge-shaped/lobar/segmental distribution
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Focal fatty sparing
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Direct drainage of hepatic blood into systemic circulation
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Gallbladder bed: Drained by cystic vein
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Segment 4 or anterior to portal bifurcation: Drained by aberrant gastric vein
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No mass effect with undisplaced vessel
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Top Differential Diagnoses
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Steatohepatitis
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Fatty cirrhosis
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Hemangioma
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Metastasis or lymphoma
Clinical Issues
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Nonalcoholic fatty liver disease may progress to nonalcoholic steatohepatitis, which may progress to fibrosis and cirrhosis
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Cirrhosis is major risk factor for hepatocellular carcinoma
Scanning Tips
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Look for undistorted vessels running through regions of steatosis
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Ensure overall gain is set correctly; gain set too high can increase apparent echogenicity of liver and mimic steatosis