Background: Although cervical spine CT (CSCT) accurately detects bony injuries, it may not identify all soft tissue injuries. Although some clinicians rely exclusively on a negative CT to remove spine precautions in unevaluable patients or patients with cervicalgia, others use MRI for that purpose. The objective of this study was to determine the rates of abnormal MRI after a negative CSCT.
Methods: Blunt trauma patients who either were unevaluable or had persistent midline cervicalgia and underwent an MRI of the C-spine after a negative CSCT were enrolled prospectively in eight Level I and II New England trauma centers. Demographics, injury patterns, CT and MRI results, and any changes in cervical spine management as a result of MRI imaging were recorded.
Results: A total of 767 patients had MRI because of cervicalgia (43.0%), inability to evaluate (44.1%), or both (9.4%). MRI was abnormal in 23.6% of all patients, including ligamentous injury (16.6%), soft tissue swelling (4.3%), vertebral disc injury (1.4%), and dural hematomas (1.3%). Rates of abnormal neurological signs or symptoms were not different among patients with normal versus abnormal MRI. (15.2 vs. 18.8%, p = 0.25). The c-collar was removed in 88.1% of patients with normal MRI and 13.3% of patients with an abnormal MRI. No patient required halo placement, but 11 patients underwent cervical spine surgery after the MRI results. Six of the eleven had neurological signs or symptoms.
Conclusions: In a select population of patients, MRI identified additional injuries in 23.6% of patients despite a normal CSCT. It is uncertain if this is a true limitation of CT technology or represents subtle injuries missed in the interpretation of the scan. The clinical significance of these abnormal MRI findings cannot be determined from this study group.
Level of evidence: Therapeutic study, level IV.