Fig. 12

Retroclival epidural haematoma in a 12-year-old female who was a pedestrian struck by a car travelling at high speed: a axial non-contrast CT brain image through the posterior fossa demonstrates hyperdense retroclival abnormality (white arrow) in keeping with epidural haematoma; b: coronal reformatted CT image of the craniocervical junction of the same patient demonstrates a left basiocciput fracture extending to the left occipital condyle (type II occipital condyle fracture pattern; black arrows). There is asymmetrical widening of the right lateral atlanto-dental space raising the likelihood of right alar ligament disruption; c: sagittal T2-weighted image of the same patient through the craniocervical junction demonstrates the retroclival epidural haematoma (short white arrows) associated with traumatic signal change oedema and haemorrhagic fluid tracking between the deep and superficial layers of the anterior atlanto-occipital membrane (thin long white arrow) and around the membrane over the superior aspect of the anterior arch of the C1 vertebra (atlas; black arrow); d: axial T2-weighted image through the craniocervical junction at the level of the occipital condyles of the same patient with magnified inset demonstrating an intact left alar ligament (white arrow) but loss of integrity of the right alar ligament in the comparative contralateral location as a result of rupture. A traumatic oedematous contusion signal abnormality is present in the right and central cervico-medullary parenchyma (black arrow)