Acute Subdural Hemorrhage

This article is an answer to the Case – 30 Years Old Man Involved in Motor Vehicle Accident

CT scan findings

  • There is subdural hemorrhage at right fronto-temporo-parietal region
  • Areas of hypodensity seen (red arrows) within the hemorrhage representing Swirl Sign
  • There is midline shift to the left side
  • Compression of ipsilateral lateral ventricle

Swirl Sign in Acute Dubdural Hemorrhage
Swirl Sign in Acute Dubdural Hemorrhage

Swirl Sign

  • Swirl sign is seen in non-contrast CT brain in acute extradural or subdural hemorrhage.
  • It represents unclotted blood which is hypodense compared to surrounding clotted blood which is hyperdense (50-70HU). 
  • It has been verified as active bleeding site at the time of surgery
  • Identification of patients with a potential risk for hematoma expansion in acute intracranial hemorrhage is crucial for planning of the treatment and prediction of the functional outcome.
  • Swirl sign is an indicator of possible hematoma expansion and associated with higher mortality compared to patient without this sign.