What shape is associated with an epidural hematoma?

An epidural hematoma is characterized by a lenticular or "moon shape." This shape arises due to the nature of the bleeding associated with epidural hematomas, which typically occurs between the outer layer of the dura mater and the skull. The accumulation of blood in this space generates a convex, lens-shaped mass on imaging, often appearing as a bulge that is limited by the sutures of the skull.

The behavior of the hematoma is also influenced by the rigid structure of the skull, as it expands outward and is constrained at its edges. The crescent or moon-like appearance distinguishes it from other types of hematomas, such as subdural hematomas, which have a more crescent shape but often appear more diffuse. Recognizing this distinct shape is essential for accurate diagnosis and management in critical care settings.