Cervical spondylosis: Evaluation of microstructural changes in spinal cord white matter and gray matter by diffusional kurtosis imaging

Abstract

Introduction: We investigated microstructural changes in the spinal cord, separately for white matter and gray matter, in patients with cervical spondylosis by using diffusional kurtosis imaging (DKI).

Methods: We studied 13 consecutive patients with cervical myelopathy (15 affected sides and 11 unaffected sides). After conventional magnetic resonance (MR) imaging, DKI data were acquired by using a 3T MR imaging scanner. Values for fractional anisotropy (FA), apparent diffusion coefficient (ADC), and mean diffusional kurtosis (MK) were calculated and compared between unaffected and affected spinal cords, separately for white matter and gray matter.

Results: Tract-specific analysis of white matter in the lateral funiculus showed no statistical differences between the affected and unaffected sides. In gray matter, only MK was significantly lower in the affected spinal cords than in unaffected spinal cords (0.60±0.18 vs. 0.73±0.13, P=0.0005, Wilcoxon's signed rank test).

Conclusions: MK values in the spinal cord may reflect microstructural changes and gray matter damage and can potentially provide more information beyond that obtained with conventional diffusion metrics.

Keywords: Apparent diffusion coefficient; Cervical spondylosis; Diffusional kurtosis; Fractional anisotropy; Gray matter; Spinal cord.