Skull Fracture

  • Etiology: trauma
  • Imaging:
    — Linear – simple fracture with the skull fragments closely approximated
    — Diastatic – complex fracture with the skull fragments spread apart
    — Depressed – complex fracture with the skull fragments entering into the cranium
    — Ping Pong – etiology is depression of plastic fetal skull against maternal sacral promontory or forceps, usually no intracranial injury, clinically spontaneously resolve
    — Growing (leptomeningeal cyst) – etiology is following diastatic fracture, dura is interrupted and there is erosion of fracture edges due to CSF pulsation, clinically is unique to infants less than 3 years old,
    — Healing – skull fracture, which involve membranous bone, heals without periosteal reaction and slowly disappears
  • DDX: accessory suture, vascular groove, Wormian bones are fracture mimics

Cases of Skull Fracture

Radiograph of a linear skull fracture
Lateral radiograph of the skull shows bilateral linear parietal lucencies coursing across the skull.
CT of a diastatic skull fracture
3D reconstruction from a CT without contrast of the brain shows a wide right parietal lucency between two separated fragments of bone.
CT of a depressed skull fracture
Axial CT without contrast of the brain shows depression of the skull in the left temperoparietal region with an associated subgaleal hematoma containing subcutaneous air.
Radiography of a growing skull fracture (leptomeningeal cyst)
3D CT reconstruction initially (left) showed a diastatic skull fracture which has increased in size on the lateral radiograph of the skull (right) taken 2 months later.
CT of an (not) accessory skull suture
3D reconstruction from CT without contrast of the brain (left) shows a linear straight lucency that connects to the left lambdoid suture. Coronal CT (right) shows the same linear lucency lying under a large subgaleal hematoma.
Radiographs of a healing skull fracture
Lateral radiograph of the skull initially (left) showed bilateral linear parietal lucencies coursing across the skull which are no longer seen 4 months later (right).
Radiograph of parietal skull fracture and CT of chronic subdural hematomas in child abuse
AP radiograph of the skull shows a linear lucency in the left parietal bone that connects to the left lambdoid suture. Axial CT without contrast of the brain shows bilateral low density extra-axial fluid collections around the brain.
Radiograph of stellate skull fracture and CT of acute subdural hematoma due to accidental trauma
AP and lateral radiographs of the skull show numerous branching lucencies in the right parietal bone. Axial CT without contrast of the brain shows high density material in the right subgaleal tissues, a small high density cresenteric fluid collection in the right extra-axial space that extends posteriorly along the falx, and a mixed low-density and high density lesion in the right posterior parietal brain parenchyma.
CT of subgaleal hematoma, diastatic skull fracture, depressed skull fracture, cerebellar contusion, diffuse cerebral edema in child abuse
Axial CT without contrast of the brain shows high density material in the subgaleal tissues posteriorly, a wide lucency in the right posterior skull along with two areas of depressed lucency in the left frontal skull, a rounded high-density lesion in the midline of the cerebellum, and decreased density of the cerebrum when compared to the normal density of the cerebellum along with loss of the normal gray matter-white matter differentiation.