Blunt craniocervical artery injury in cervical spine lesions: the value of CT angiography.

OBJECTIVE: The awareness of traumatic craniocervical artery injuries has increased over the last years, and the detection rate varies in published trauma series. These injuries are often associated with cervical spinal and cranial trauma. The purpose of this prospective study was to determine the frequency and injury characteristics of blunt traumatic cervical artery injuries in patients suffering from cervical spine injuries by using a standardized CT angiography (CTA) protocol of the craniocervical vessels. METHODS: Over a period of 32 months (February 2006 to September 2008), we prospectively evaluated 53 patients with osseous cervical spine injuries. Of these, 41 patients were screened for blunt craniocervical vessel injuries using CT angiography in 718 consecutive patients requiring a whole-body trauma CT due to the mechanism of their injury and injury patterns. All examinations were performed using a 16-row multi-slice computed tomography (Sensation 16, Siemens, Erlangen, Germany). Initially, a scan of the neurocranium angulated in orbito-meatal orientation was acquired. Then, a CT angiography of the craniocervical vessels with 40 ml of iodinated contrast agent (flow 4 ml/s; 40 ml saline flush, flow 4 ml/s) was performed starting at the level of Th2 up to the roof of the lateral ventricles. The scan was started using bolus tracking. Finally, a contrast-enhanced spiral thoraco-abdominal scan was performed with a delay of 20 s after administering a second contrast bolus of 60 ml. Besides, 11 patients with already detected isolated cervical spine injury, who were not initially involved in the whole-body trauma imaging protocol, underwent a secondary CT angiography with 60 ml of contrast agent (flow 4 ml/s; 40 ml saline flush, flow 4 ml/s), starting at the level of Th2 up to the roof of the lateral ventricles. The craniocervical vessels were analyzed in the source images, with the use of maximum-intensity projections and curved multi-planar reconstructions. Alternatively, a duplex ultrasound (DUS) was performed in one patient with respect to pregnancy. RESULTS: CTA was considered adequate for diagnosis in all but one case due to reduced CTA imaging quality. In one patient, DUS instead of CTA was performed with respect to pregnancy. We detected isolated osseous cervical spine injury in 53 consecutive patients. Of these patients, 18.9% suffered from vertebral artery injuries (VAI) (14 VAI in 10 patients). Carotid artery injuries were not detected in these patients. In five (50%) patients, we observed cerebral infarction due to VAI. CONCLUSION: Craniocervical vessel injury is a life-threatening and underdiagnosed event in cases of cervical spine injury. CTA of the craniocervical vessels offers a fast, safe, and feasible method for detecting vascular injuries of the craniocervical region and allows prompt further treatment if necessary to reduce the risk of cerebral infarction. CTA of the craniocervical vessels is strongly indicated in cases of cervical spine trauma and in trauma mechanisms involving the cervical spine. Our data underscore the need for screening of blunt carotid and vertebral injury especially in injured cervical spine.