Diffusion tensor tractography as a supplementary tool to conventional MRI for evaluating patients with myelopathy

Abstract

PurposeThe aim of this study was to assess the clinical utility of DTI including apparent diffusion coefficient (ADC), fractional anisotropy (FA), in patients with symptoms of spinal cord myelopathy. Patients and methodsFifteen subjects with clinical symptoms of acute (n=3) or slowly progressive (n=12) spinal cord myelopathy and 11 healthy volunteers were prospectively selected. They all underwent magnetic resonance imaging of the spine at 3.0T machine. In addition to conventional MRI, DTI was performed; maps of the apparent diffusion coefficient and of fractional anisotropy were reconstructed. Diffusion tensor tractography was used to visualize the morphological features of normal and impaired white matter at the level of the pathological lesions in the spinal cord. The patients were divided into two groups according to the signal intensity on T2WI (group A with no change in signal intensity and group B with high signal intensity). ResultsThere were no statistically significant differences in the apparent diffusion coefficient and fractional anisotropy values between the different spinal cord segments of the normal subjects. All of the patients in group B had increased apparent diffusion coefficient values and decreased fractional anisotropy values at the lesion level compared to the normal controls. However, there were no statistically significant diffusion index differences between group A patients and the normal controls. ConclusionDiffusion tensor imaging is a reliable method for the evaluation of the diffusion properties of normal and compressed spinal cords. Furthermore, this technique can be used as an important supplementary tool to conventional MRI for the quantification of fiber damage in spinal cord compression, thus has the potential to be of great utility for treatment planning and follow up.