Diffusion tensor MR imaging in cervical spine trauma

Our aim was to investigate the extent and severity of changes in spinal cord diffusion tensor imaging (DTI) parameters in patients with cervical cord injury.

DTI was performed in 20 symptomatic patients (mean, 45.7 +/- 17.7 years of age; 2 women, 18 men) with cervical spine trauma and 8 volunteers (mean, 34.2 +/- 10.7 years of age; 6 men, 2 women). The whole cord and regional apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative anisotropy (RA), and volume ratio (VR) of patients and volunteers were compared. DTI parameters were calculated in 16 patients. MR imaging demonstrated hemorrhagic cord contusions (n = 6), nonhemorrhagic cord contusions (n = 4), and soft-tissue injury (n = 6). Medical records were reviewed for extent of neurologic deficit.

Regional ADC values differed significantly between upper and mid and upper and lower (both, P < .004) cervical cord sections. FA was significantly different between upper and lower sections (P < .03). Whole cord ADC values were significantly lower in patients than in volunteers (P < .0001). Whole spine FA was not significantly decreased in patients (P < .06). ADC and FA values were significantly decreased at injury sites when compared with volunteers (P < .031 and .0001, respectively). The greatest differences in whole cord ADC, FA, RA, and VR were in patients with hemorrhagic cord contusions compared with healthy volunteers (P < .0001, .003, .0005, and .008, respectively).

DTI parameters are sensitive markers of cervical cord injury, with ADC showing the greatest sensitivity. Changes in DTI parameters are most marked at injury sites and reflect the severity of cord injury.