Diffuse Liver Disease and Fatty Infiltration Prt1

Diffuse Liver Disease

  • Also called hepatocellular disease, affecting hepatocytes.

  • Group of disorders interfering with liver function.

  • "Diffuse" means changes throughout the entire liver parenchyma.

  • Spectrum ranges from benign (fatty infiltration) to severe (cirrhosis).

  • Progressive diseases worsen over time.

  • Can alter the liver's echogenicity and size.

  • Progressive diseases increase attenuation, making sonographic penetration harder.

Fatty Infiltration (Fatty Liver)

  • Common disorder involving increased lipid/triglyceride accumulation in liver cells.

  • Also known as fatty liver or fatty liver infiltrate.

  • Secondary to hepatocyte injury or systemic metabolic disorders.

  • Acquired condition (not congenital).

  • Reversible through diet and exercise.

  • Considered a benign condition.

Causes of Fatty Liver Infiltrate

  • Most common in the US:

    • Obesity

    • Chronic alcohol abuse (ETOH)

  • Other causes:

    • Diabetes mellitus

    • Hyperlipidemia

    • Severe hepatitis

    • Cystic fibrosis

    • Kwashiorkor (protein malnutrition)

    • Ulcerative colitis

    • Excessive overeating

    • Starvation/Prolonged fasting: Body stores fat due to perceived scarcity.

    • Reye's syndrome

    • Glycogen storage disease

    • Jejunoileal bypass surgery

    • Corticosteroid therapy

    • Pregnancy

    • Chemotherapy

  • Increased fat deposits can separate liver lobules and increase liver weight.

  • In advanced cases, liver function tests (AST, ALT) may be elevated

Ultrasound Appearance of Fatty Infiltrate

  • Varies with severity; reversible, liver may appear normal in follow-up.

    • In simple cases, liver function tests are usually normal

  • Liver size: May be enlarged or normal.

  • Echogenicity: Increased compared to renal cortex.

  • Parenchyma: Possibly has a Granular texture.

  • Portal veins are obscured due to increased echogenicity.

  • Paucity of hepatic vessels.

  • Increased attenuation of sound (harder to penetrate), making it difficult to visualize deeper portions and the diaphragm; may see a break in the diaphragm.

  • Appearance: Similar to marbling in a steak.

Ultrasound images of fatty infiltrate liver

  • Liver is much more echogenic than the cortex of the kidney.

  • Granular texture within

  • Liver is larger than normal

  • Increased overall liver echogenicity when compared to the renal cortex.

  • Obscurity of portal veins and hepatic veins because of the brightness.

CAT scan of fatty infiltrate liver

  • Enlarged liver.

  • Marbling within the liver - echogenic areas.

Focal Fatty Infiltrate

  • Localized area(s) of increased echogenicity within otherwise normal liver tissue.

  • Small portions of the parenchyma are affected.

  • Areas appear hyperechoic within normal echogenicity tissue.

  • Pitfall: Can be mistaken for a mass.

  • Often followed up with CT scan to differentiate from a mass.

  • Focal: Localized; Diffuse: All over.