Clinical Study and Comparison of Magnetic Resonance Angiography (MRA) and Angiography Diagnosis of Blunt Vertebral Artery Injury

Abstract

Two-dimensional time-of-flight (2D TOF) magnetic resonance angiography (MRA) is the major method for detecting vertebral artery injury (VAI). But there is still controversy over MRA's accuracy in detecting VAI of varying degrees, a technique for which there are no animal studies found in the literature. The purpose of this study was to evaluate the value of MRA for detecting vertebral artery injury in cervical spinal trauma patients and to conduct a comparative study of MRA and angiography of blunt vertebral artery injury in an animal experiment. In clinical study, 319 patients with close cervical spinal trauma underwent 2D TOF MRA prospective examination. The strike-induced flexion injury model of the cervical spine was constructed based on animal experiment with 14 adult dogs. X-ray studies were performed immediately after injury. 2D TOF MRA and angiography were formed within 24 to 36 hours. Vertebral artery injury was detected by 2D TOF MRA in 52 of the 319 patients. Of the 52 patients, there were 51 unilateral vertebral artery injuries, including 22 injuries on the left vertebral artery and 29 on the right vertebral artery. One patient sustained bilateral vertebral artery injury. Seven dogs had unilateral VAI (5 on the left, 2 on the right), and two dogs had narrower-than-normal left vertebral arteries on MRA examination. Angiography showed occlusion exactly in seven dogs with unilateral vertebral artery injury detected by MRA and no abnormal findings were detected in five dogs without vertebral artery injury on MRA. In two dogs with incomplete left vertebral artery flow-related enhancement on MRA, angiography showed occlusion in one dog and no vertebral injury with normal image in the other. 2D TOF MRA is an effective detection method of blunt vertebral artery injury but it might not be able to differentiate spasm, a small disruption of intima, from others under certain conditions.