MRI Correlates of White Matter Structure in Intact Myelin Vs. Myelin Debris ex Vivo Study in Injured Rat Spinal Cord

Henry S. Chen¹, Jie Liu², Wolfram Tetzlaff², Piotr Kozlowski

Diffusion tensor imaging, quantitative T2, and T1 mapping were used to characterize excised rat spinal cord samples at 3 weeks post injury. Comparisons were made between injured and controlled white matter for several MR parameters, as well as for optical and electron microscopy cross-sections. Axonal damage is demonstrated by decrease in longitudinal diffusivity and fraction anisotropy, while myelin damage is more difficult to assess due to the presence of myelin debris. However the result did show increased myelin water content which is consistent with the histology result which showed increased spacing between myelin bi-layers in myelin debris.