Saeed Fakhran
The evaluation of patients following cervical spine trauma is an integral part of any busy neuroradiology practice. CT is usually the first imaging modality obtained in these patients, having long supplanted plain film imaging. While CT is known to provide exquisite detail of the bony anatomy of the cervical spine and is an excellent tool to exclude acute bony injury, patients with spine trauma can often have clinically significant ligamentous injury in the absence of a bony abnormality. In fact, the risk for neurologic sequelae is 10 times higher in patients with cervical injury missed on initial screening.
Catastrophic ligamentous injury may result in cervical instability and acute disability, whereas subcatastrophic injury may lead to chronic pathologic conditions, including disc degeneration, facet osteoarthritis, and chronic instability. Even in patients with other known cervical spine injuries, an unrecognized disc or ligament injury can be devastating, as potentially a higher number of columns may be injured. Identifying disruption of ligamentous integrity, even in the setting of known fractures, is critical, as knowledge of the extent of cervical column compromise is important in alerting clinicians to the potential for delayed instability.
Unfortunately, CT assessment of ligamentous injury remains highly subjective, heavily reliant on vertebral body alignment and disc widening. Such subjective analysis often leads to highly variable sensitivity between observers, to the detriment of patient care and the frustration of our clinical colleagues. We sought to develop a uniform, reproducible, and easily applied measurement to aid in identification of injury to the anterior discoligamentous complex—of which the anterior longitudinal ligament is a major component—of the cervical spine.