Clinical value of diffusion tensor imaging parameter value in evaluating the prognosis of spinal cord injury in acute cervical spinal cord injury

Objective: To evaluate the clinical application value of diffusion tensor imaging (DTI) parameter in evaluating the prognosis of spinal cord injury in acute cervical spinal cord injury. Method: From October 2012 to December 2015, a total of 23 patients with acute cervical spinal cord injury were examined by routine MRI-T2WI high signal DTI examination, according to the American Spinal Injury Association (ASIA) damage standard. One month later according to the functional outcome of the spinal cord, all patients were divided into non improvement group (group A) 4 cases (2 cases of ASIA-A, 2 cases of grade B) and improvement group (group B) 19 cases (13 cases of ASIA-C, 5 cases of grade D, 1 case of grade B), 15 cases of healthy volunteers as the normal group (group C ). The FA value, ADC and axial eigen value[λ∥=λ1], radial eigen value[λ⊥=(λ2+ λ3)/2]of before and after the treatment in group A and group B were compared by paired t test respectively. Single factor analysis of variance (ANOVA) was used to analyze the differences of DTI among the group A, group B and group C, and LSD test was used to compare the differences among the groups.Before and after treatment, the DTI measurement area was consistent.Changes of nerve fiber bundles in group A and group B before and after treatment were displayed in DTT. Results: After the treatment , the FA value of group A decreased , ADC value and λ⊥ value increased than that of before treatment(t=3.037, -4.183, -4.805, all P 0.05). After the treatment , the FA value and ADC value of group B increased , λ⊥ value decreased than that of before treatment(t=-3.344, -3.642, 4.694, all P 0.05). After treatment, there were statistical differences in FA values, λ⊥ value , ADC values and λ∥ values among three groups (F=71.958, 70.432, 75.902, 22.521, all P<0.01). Conclusion: The changes of FA value, λ⊥ value are the two most sensitive indicators of acute cervical spinal cord injury of spinal cord function prognosis.It suggests the poor prognosis of spinal cord function when FA value decreases and λ⊥ value continues to increase.DTT can visually display subtle changes in the nerve fiber bundle.