1. Pathogenesis:
- Acute hepatitis of any origin causes the
hepatocytes to become edematous. Clinical correlation is more helpful in
diagnosis of hepatitis while role of liver imaging is limited.
- Hepatitis can cause enlarged liver
without focal disease.
- Hepatitis A is transmitted fecal-orally.
Clinical manifestations are usually fatigue, weakness, vague abdominal
pain, hepatomegaly (85%), and splenomegaly (15%).
- Hepatitis B is typically acquired through I.V.
drug use, sex, or blood transfusion. 5% will become chronic. Less than
1% will be fulminant. Hep B infection does increase risk for cirrhosis,
portal HTN, HCC.
- Hepatitis C is mostly acquired via
transfusion, sex, or I.V. drug use.
- Radiographic findings:
- There are no definite abnormalities on
imaging in both acute and chronic hepatitis.
- U/S: In acute, either entirely normal or
may have a "starry sky" appearance (decreased echogenicity of the
parenchyma with prominence of the portal venous system). In chronic,
there may be a coarsely echogenic parenchymal pattern.
- CT or MRI: not used to evaluate acute
hepatitis.
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