Diffusion tensor MR imaging of the neurologically intact human spinal cord

Area of Science:

• Neuroimaging
• Biophysics

Background:

• Diffusion properties of the entire human spinal cord are crucial for understanding pathologic conditions.
• Standardized data are needed for comparing spinal cord imaging results.

Purpose of the Study:

• To characterize in vivo diffusion properties of the entire human spinal cord.
• To provide normative data for clinical comparisons and pulse sequence optimization.

Main Methods:

• 13 neurologically intact subjects underwent diffusion-weighted echo-planar imaging (EPI).
• Axial images covered the entire spinal cord (C1-L1) using a single-shot, twice-refocused spin-echo sequence.
• Acquisition time was 45 minutes.

Main Results:

• Diffusion imaging revealed gray and white matter contrast despite minor geometric distortions.
• Diffusion coefficients varied along the cord length.
• Key metrics included mean diffusivity (MD) of 0.83 ± 0.06 x 10⁻³ mm²/s and fractional anisotropy (FA) of 0.49 ± 0.05.

Conclusions:

• Normative diffusion values for the entire spinal cord were established.
• These data support comparisons with spinal cord pathologies.
• Findings can inform improvements in MRI pulse sequence design for spinal cord imaging.