Traumatic subaxial cervical spine injury – Improving initial evaluation through correlation of diffusion tensor imaging and subaxial cervical spine injury classification SLIC score

Abstract

Background: Traumatic injury to spine and spinal cord represents a devastating condition, with a huge risk for permanent severe disabilities. Predicting the long-term outcome in this type of trauma is a very difficult task being under the influence of a wide spectrum of biomechanical and pathophysiological factors. The advent of magnetic resonance imaging (MRI) structural evaluation of the spinal cord brought critical supplementary data in the initial evaluation of these cases. Although edema and hemorrhage proved to be valuable in predicting the outcome, there is a well-documented discrepancy between MRI findings and clinical status. Methods: We performed diffusion tensor imaging (DTI) MR in 22 symptomatic patients with traumatic cervical spine injuries (mean age 49.6 ± 16, range from 17 to 74 years, 20 males and 2 females). DTI parameters were computed in 15 patients. Regional apparent diffusion coefficient, fractional anisotropy (FA), and fiber length (FL) were calculated in the region of interest defined as the region of maximum structural MR alterations and in the normal cord (above or below the level of the injury). The values for normal and pathological cord were compared. The clinical deficit was assessed with ASIA and subaxial cervical spine injury classification (SLIC) scores. We looked at the correlation between the DTI measures and clinical scores. Results: There is a highly significant difference between normal and pathological spinal cord for all DTI properties measured. There is also a strong correlation between DTI measures and SLIC clinical score, especially for FA. Significant results were obtained for CDA and FL as well although with lesser statistical power. Conclusion: Our results suggest that DTI measures, especially FA, represent a strong indicator of the severity of the traumatic cervical cord injury. It correlates very well with SLCI score and can be used as an additional confirmation of the real degree of level lesioning and as a prognostic factor for the neurological outcome regardless of the choice of treatment.