Prediction of prognosis in patients with cervical spinal cord injury without radiologic evidence of trauma using MRI.

The purpose of this study was to investigate whether pre- to postoperative changes of increased signal intensity (ISI) of the spinal cord as seen on T2-weighted magnetic resonance imaging (MRI) reflect the surgical outcome in patients with cervical spinal cord injury without radiologic evidence of trauma (SCIWORET). In this study, 54 patients with SCIWORET who underwent expansive laminoplasty were retrospectively analyzed. All patients underwent MRI at an average of 1.9 days (range, 1-5 days) after injury and 7.9 days (range, 6-10 days) postoperatively. The pre- and postoperative range and degree of ISI were measured on computer software using the same sagittal view on T2-weighted MRI. Then, the post-preoperative ratio of range and degree of ISI were calculated. Pre- and postoperative neurologic evaluations were performed according to the criteria proposed by the Japanese Orthopedic Association (JOA). A significant negative correlation existed between the ratio of range of ISI and the recovery rate (r=-0.504, P<.01). The ratio of degree of ISI negatively correlated with the recovery rate, but this was not statistically significant. Patients were divided into 2 groups according to the ratio of degree of ISI: group A included patients with a ratio of degree of ISI of ≤1 (n=24) and group B included patients with a ratio of degree of ISI of >1 (n=30). Patients' mean recovery rate was 65.0%±6.3% in group A and 52.4%±7.4% in group B. A significant difference was found between the 2 groups (P<.001, Student's t test) when comparing recovery rate. The pre- to postoperative changes of the range and degree of ISI significantly reflected prognosis for surgical outcome in patients with SCIWORET.