Presentation
Young male brought by ambulance with history of MVA.
Patient Data
Subdural hemorrhage surrounding the right cerebral hemisphere with tentorial and falcine extension. Midline structures shifted to the left.
The aforementioned subdural hematoma demonstrates a swirl sign suggesting active bleeding. Minimal left frontal subdural hemorrhage seen.
Right hemispheric cerebral edema was noted. No cerebral herniation noted.
Case Discussion
The swirl sign is a radiological sign of acute extravasation of blood into a hematoma on non-contrast CT. It represents unclotted fresh blood which has lower attenuation compared to clotted blood, and this is suggestive of active bleeding.
Active bleeding gives the same appearance of contrast extravasation on CT angiogram but additionally contrast extravasation may be seen as the CTA spot sign.
Special thanks to Dr Tamer Elholiby.