subgaleal hemorrhage
Subgaleal hematoma describes scalp bleeding in the potential space between the periosteum and the galea aponeurosis. It is a rare but possibly lethal emergency.
Epidemiology
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. In patients with intracranial hemorrhage or skull fractures, the incidence of subgaleal hemorrhage is increased.
Clinical presentation
Signs include pallor on inspection. On examination, there may be tachycardia, hypotonia. A fluctuant scalp mass with increasing head circumference may be seen on palpation.
Pathology
Etiology
Bleeding occurs as a result of rupture to emissary veins which drain the scalp veins into the dural sinuses.
Location
Due to being superficial to the periosteum, subgaleal hematomas are able to cross suture lines and canvas the entire skull.
Radiographic features
Ultrasound
- blood of moderate echogenicity
- decreasing echogenicity with time
- not bound by periosteum
CT
- more objective measurement of hematoma volume
- determine presence of an underlying skull fracture
Radiology report
- size of the hematoma
- content of the fluid collection
- presence of an associated fracture
Differential diagnosis
General imaging differential considerations include:
- scalp hematoma
- caput succedaneum
- subgaleal hematoma
- cephalohematoma
- subgaleal abscess
On certain MRI sequences also consider: