What shape does an epidural hematoma typically present on a CT scan?

An epidural hematoma typically presents on a CT scan as a lens-shaped or biconvex mass. This characteristic shape results from the accumulation of blood between the dura mater and the skull, often due to a rupture of the middle meningeal artery, which is frequently associated with skull fractures.

The lens shape is distinct because it bulges outward and does not cross suture lines of the skull due to the dural attachments. This shape helps in differentiating an epidural hematoma from other types of hematomas, such as a subdural hematoma, which presents with a crescent shape and can cross suture lines. Understanding the typical imaging features of an epidural hematoma is crucial for timely diagnosis and management, as it can lead to significant neurological deficits if not treated promptly.