MR Angiography Detection of Occult Vertebral Artery Injuries following Cervical Spine Trauma

To determine the prevalence of vertebral artery injury following cervical spine trauma using magnetic resonance angiography (MRA).

Patients with cervical spine trauma referred for MR were prospectively imaged using 3D time-of-flight angiography to visualise the extracranial vertebral arteries. Patients were assessed clinically for vertebral basilar ischaemia prior to imaging. MR angiograms were assessed by two neuroradiologists blinded to the clinical status. Vertebral arteries were assessed as: normal, abnormal, absent. If clinically indicated, follow-up digital angiography was performed.

25 patients were evaluated. Age range 20–64 years, mean 25 years old. 15 patients (60%) were quadraparetic or paraparetic. There was no clinical evidence of vertebral basilar ischaemia. Commonest injuries were flexion subluxation/dislocations or rotational injuries, followed by hyperextension injuries and burst fractures. MRA abnormalities were detected in 10 patients (40%). In 8 patients there was absence of 1 artery confirmed in 6 as occlusions on angiography, in 2 there were contour abnormalities which were confirmed to be dissections on angiography. Commonest site of injury was: C5/6, C1/2. Cord contusions were detected in 15 patients. There was no correlation between the severity of cord and bony injury and vertebral artery injury.

Clinically occult vertebral artery injury is common in patients following cervical spine trauma. Arterial occlusions are more common than dissections. Routine MRA during MR spine imaging is recommended to identify these patients who may require anticoagulation and careful follow-up.