Age-related changes of the diffusion tensor imaging parameters of the normal cervical spinal cord

The diffusion tensor imaging (DTI) parameters of the cervical spinal cord (CSC) changes with age. However, previous studies only examined specific CSC areas.

To analyze the DTI parameters in all intervertebral space levels of the whole normal CSC and to study the impact of age on these parameters in a Chinese population.

Thirty-six healthy subjects aged 20-77 years were recruited. DTI parameters were calculated for gray matter (GM) and white matter (WM) funiculi in all the CSC intervertebral spaces (C1/2-C6/7). Age-related changes of DTI parameters were analyzed for the GM and WM funiculi.

Fractional anisotropy (FA) and mean diffusivity (MD) were lower in GM than in WM. MD and FA values were lower in the WM in the lower CSC compared with the upper CSC (all P<0.05), but no difference was observed in GM. In ventral funiculi, MD increased with age, while FA decreased (all P<0.001). In lateral and dorsal funiculi, MD and FA decreased with age (all P<0.001). In GM, MD and FA decreased with age (all P<0.001). Significant age-related changes were observed in FA and MD from GM and WM funiculi. FA was correlated with age in all funiculi (ventral: r=-0.733; lateral: r=-0.468; dorsal: r=-0.607; GM: r=-0.724; all P<0.01).

Important changes in MD and FA were observed with advancing age at all levels of CSC in Chinese patients. DTI parameters may be useful to assess CSC pathology, but the influence of age and segments need to be taken into account in diagnosis.