Starry sky appearance (ultrasound)

A starry sky appearance refers to a sonographic appearance of the liver parenchyma in which there are bright echogenic dots throughout a background of decreased liver parenchymal echogenicity. Although usually associated with acute hepatitis, this sign has been found to have poor sensitivity and specificity .

Terminology

This ultrasound sign should not be confused with the similarly named starry sky appearance (MRI) seen in multiple biliary hamartomas and the milky way sign (MRI) seen in progressive multifocal leukoencephalopathy (PML).

Pathology

It is thought to occur due to the edematous swelling of hepatocytes with a resultant decrease in the hepatic echogenicity. The altered acoustic properties between the portal venous radicles and hepatic lobules cause sonographic accentuation of the venule walls.

Etiology

• acute hepatitis
• toxic shock syndrome
• leukemic infiltration of the liver
• diffuse neoplastic infiltration, primary or metastatic
• opportunistic infections
• fasting liver
• Burkitt lymphoma involving the liver
• right heart failure
• pre-eclampsia and HELLP syndrome