Subgaleal hematoma

Last revised by Kevan English on 4 Oct 2023

Subgaleal hematoma describes scalp bleeding in the potential space between the periosteum and the galeal aponeurosis. It is a rare but possibly lethal emergency.

Moderate to severe presentations occur in 1.5 of 10,000 live births. It most commonly occurs after vacuum-assisted and forceps delivery, but may also be seen following head trauma or occur spontaneously. The association with vacuum extraction is as high as 89% of cases 4. In patients with intracranial hemorrhage or skull fractures, the incidence of subgaleal hemorrhage is increased 4.

Signs include pallor on inspection. On examination, there may be tachycardia and/or hypotonia. A fluctuant scalp mass with increasing head circumference may be seen on palpation.

As the potential space extends into the neck, a subgaleal hematoma may also extend into the neck. This is in contrast to a cephalohematoma which remains confined to the skull and will not cross suture lines 4

Bleeding occurs as a result of rupture to emissary veins which drain the scalp veins into the dural sinuses.

Due to being superficial to the periosteum, subgaleal hematomas are able to cross suture lines and surround the entire skull.

  • blood of moderate echogenicity
  • decreasing echogenicity with time
  • not bound by periosteum
  • more objective measurement of hematoma volume
  • enables to determine presence of an underlying skull fracture
  • size of the hematoma
  • content of the fluid collection
  • presence of an associated fracture

General imaging differential considerations include:

On certain MRI sequences also consider:

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