Relationship between magnetic resonance imaging findings and spinal cord injury in extension injury of the cervical spine

Objective: The purpose of this study was to determine the relationship between magnetic resonance imaging (MRI) findings and neurologic symptoms in cervical spine extension injury and to analyze the MRI parameters associated with neurologic outcome. Materials and methods: This study included 102 patients with cervical spine extension injury, whose medical records and MRI scans at the time of injury were available. Quantitative MRI parameters such as maximum spinal canal compression (MSCC), maximum cord compromise (MCC), and lesion length showing intramedullary signal changes were measured. Furthermore, intramedullary hemorrhage, spinal cord edema, and soft tissue damage were evaluated. Fisher’s exact test was used for a cross-analysis between the MRI findings and the three American Spinal Injury Association category groups depending on the severity level of neurologic injury: complete (category A), incomplete (categories B–D), and normal (category E). Results: MSCC accounted for 23.05, 19.5, and 9.94 % for the complete, incomplete, and normal AIS categories, respectively, without showing statistically significant differences (P = 0.085). MCC was noted in 22.05, 15.32, and 9.2 %, respectively, with the complete-injury group (AIS category A) showing significantly higher. In particular, cases of complete injury had >15 % compression, accounting for 87.5 % (P < 0.001). The mean intramedullary lesion length was significantly higher in complete-injury patients than in incomplete-injury patients (24.22 vs. 8.24 mm). Intramedullary hemorrhage and spinal cord edema were significantly more frequently observed in complete-injury cases (P < 0.001). The incidence of complete injury was proportional to the severity of soft tissue damage. Conclusion: MCC, intramedullary lesion length, intramedullary hemorrhage, and spinal cord edema were MRI parameters associated with poor neurologic outcomes in patients with cervical spine extension injury.