Head CT > Trauma > Acute Subdural Hematoma


Acute Subdural Hematoma

Deceleration and acceleration or rotational forces that tear bridging veins can cause an acute subdural hematoma. The blood collects in the space between the arachnoid matter and the dura matter. The hematoma on CT has the following characteristics:
- Crescent shaped
- Hyperdense, may contain hypodense foci due to serum, CSF or active bleeding
- Does not cross dural reflections



High density, crescent shaped hematoma (arrowheads)
overlying the right cerebral hemisphere. Note the shift of the
normally midline septum pellucidum due to the mass effect arrow.


The hypodense region (arrow) within the high density
hematoma (arrowheads) may indicate active bleeding.