Epidural space

The epidural space is the potential space between the bones of the cranial cavity and the periosteal dura.  Damage to one of the meningeal arteries can lead to an epidural hematoma, in which the high-pressure arterial blood pushes it way between the dura and the skull.  An epidural hematoma has a characteristic lenticulate (lens-shaped) shape, because the edges of the dura at the edge of the hematoma are still attached to the skull.