Degenerative Cervical Myelopathy (DCM) is a cause of spinal cord dysfunction affecting 2% of population.Loss of axonal integrity has been implicated in DCM, but its role is to be determined in DCM with neck pain. Diffusion Tensor imaging (DTI) is a Magnetic Resonance (MR) technique capable of measuring magnitude and direction of diffusion of water molecules in tissues. Direction dependent diffusion is anisotropy, used by DTI to infer the orientation of surrounding axonal fibres and to delineate anatomical boundaries. Fractional anisotropy (FA) defines the degree of anisotropy. ADC (apparent diffusion coefficient) or Mean diffusivity (MD) is the average of the diffusivities in the 3 principal axes.
Purpose: To compare the FA and ADC values obtained by DTI in healthy and neck pain to assess the microstructural damage of the spinal cord in DCM.
Methods: MRI DTI images from subjects with or without neck pain will be obtained. FA and ADC will be estimated and compared. In Phase 1, one with and one without neck pain were scanned to establish methodology. First a sagittal T2W turbo spin echo (TSE) was acquired to evaluate spinal cord status. Second, axial T2- weighted (T2*W), multi-echo fast field echo (mFFE) images with three echoes were acquired for anatomical references. Third, a multi-shot high-resolution DTI data were acquired using a two-dimensional navigated interleaved EPI sequence.
Results: Healthy individual [62M] and neck pain individual [69M] successfully underwent MRI in a Phillips 3-T Achieva TX scanner, scan time was 45 mins per patient. T2- weighted images were acquired using a 16-channel neurovascular radiofrequency (RF). Healthy FA was 0.83, neck pain FA was 0.543. Healthy ADC was 0.17 and neck pain ADC was 0.13.
Conclusion: We have successfully established a protocol for spinal cord DTI evaluation. We expect a positive correlation between worsened symptoms and a lower axonal integrity. DTI of the cervical spine may be a promising novel imaging modality for patients with DCM.