What shape is characteristic of an epidural hematoma on imaging?

An epidural hematoma is characterized by a biconvex shape on imaging studies, most commonly seen in CT scans of the head. This specific shape arises due to the accumulation of blood between the dura mater and the skull following a rupture of a blood vessel, such as an arterial injury from trauma. The biconvex shape is indicative of the mass effect that results as the hematoma expands, creating a convex profile that bulges outward on both sides. This appearance can be contrasted with other types of hematomas or injuries, such as subdural hematomas, which typically have a crescent or concave shape due to their location between the dura and the brain. The biconvex nature of an epidural hematoma is crucial for clinicians in diagnosing and determining the appropriate course of treatment for traumatic brain injuries.