Identification of type 1: interforaminal vertebral artery anomalies in cervical spine MRIs

STUDY DESIGN: This is a prospective study. OBJECTIVE: The aim of our study is to identify whether vertebral arteries (VA), normal or aberrant, are routinely described in cervical spine magnetic resonance imaging (MRI) interpretations. SUMMARY OF BACKGROUND DATA: VA injury is a serious complication of anterior cervical spine surgery. Aberrant VA anatomy is a potential cause of such complications. Therefore, VA anatomy should be evaluated in cervical MRIs. METHODS: Six neuroradiologists were blinded to the study design and were asked to interpret 79 cervical MRIs. Of these, 39 had aberrant VAs, whereas 40 had normal VAs. Initially, the indications for the study included only a description of patient's symptoms. The radiologists were then given the same MRIs with different indications. This time, the indications included the patient's symptoms, a request for annotations on the VA, and a definition of VA anomaly. All of the MRI interpretations were then evaluated for the frequency and accuracy of VA description. RESULTS: When the indications for the study did not specifically request a comment on VAs, the VA was never described (0%). When the indications included the specific request and definition, all 6 commented on the VA (100%). Three of the 6 radiologists were 100% accurate in identifying all 40 normal and 39 aberrant VAs, whereas the other 3 identified all 40 normal and 38 of 39 aberrant VAs. CONCLUSION: This study demonstrates that the VA is not a standard component of cervical spine MRI interpretations. Because of the significant complications related to its injury, VA anatomy, whether normal or variant, needs to be evaluated in cervical MRIs. When ordering a cervical MRI, surgeons should request a description of the VA and any anomalies.