Atlanto-occipital dislocation

There is a dislocation of the occipital condyles (left and right) ventrally on the C1 lateral masses. There is significant prevertebral edemaoedema from the skull base through C4. Additional soft tissue stranding and edema isoedema are seen in the right lateral neck and along the left scalene musculature, which is also concerning for sequelae of trauma and soft tissue injury.There is soft tissue density dorsal to the thecal sac at the C1-C2 level concerning for edema anoedema and/or epidural hematomahaematoma with possible ligamentous injury. There is a widening of the dorsal interspace between C1 and C2.There is congenital nonunionof the posterior arch of C1.There are mild to moderate degenerative changes of the cervical spine, most pronounced at C4-C5 and C5-C6. No significant osseous canal stenosis is evident on noncontrastnon-contrast CT, but further assessment is recommended given the injury is noted above.There is a minimally displaced fracture of the posterior aspect of the medial left T1 rib.

There is redemonstration of ventrally dislocated occipital condyles on the C1 lateral masses. There is significant prevertebral edemaoedema at the level of C3, extending superiorly to the level of the nasopharynx and inferiorly to the level of T1. There are multiple subdural hematomashaematomas within the anterior upper cervical spine from C1 to C3. The cervical spinal cord maintains normal calibercalibre and signal intensity.At C1-C2, sagittal STIR images demonstrate an abnormal signal and irregularity of the tectorial membrane. There is extensive edemaoedema within the C1-C2 interspinous ligaments. The posterior atlantooccipital membrane is disrupted. There is likely disruption of the transverse ligament.There is an increased T1 signal along the anterior longitudinal ligament. No significant spinal canal or foraminal compromise.