Preliminary study on using diffusion tensor imaging in evaluation of cervical stenosis

Objective: To evaluate the effects of cervical stenosis on the diffusion tensor imaging derived parameters (apparent diffusion coefficient and fractional anisotropy, ADC and FA) at the white matters in cervical cord. Methods: Consecutive 126 patients with pain in cervical and shoulder, parenthesis and dysfunction of movement in the upper limbs underwent cervical MR scan. Thirty-four cases aged matched volunteers having no discomfort of cervical spine and shoulder were enrolled as control group. Imaging protocol included sagittal and transverse T₂ weighed imaging and diffusion tensor imaging. First we classified severity of cervical stenosis into 0 ° for volunteers and 1 ° to 3 ° for patients. Then we simplified the classification into compression and uncompression groups based on if presence of spinal cord compression. Eighty-two patients with 1 ° cervical stenosis, thirty-six patients with 2 ° stenosis and eight patients with 3 ° stenosis. The values of ADC and FA were compared among the four groups. Results: The FA values didn't significantly differ among the four groups. But the ADC values of all the regions of interest significantly differed among the four groups (P < 0.05), with a single exception at the right posterior portion (F = 1.56, P = 0.20). In the group 2 °, the ADC values at right anterior- and left anterior regions were significantly higher than that of group 0 ° and 1 °(P < 0.05). The ADC values had no differences between the 2 ° and 3 ° groups (P > 0.05). In the group 3 °, the ADC values were significantly higher than that of group 0 ° and 1 ° at all the regions of interest (P < 0.05). With exception at the right posterior portion, the ADC values in the compression group were higher than in the uncompression group. Conclusions: DTI can quantitatively evaluate the cervical cord in patients of cervical stenosis. In the early stage of compression of the cervical cord, the ADC values increase in the white matter and FA values remain unchanged. (authors)