Distribution of collateral fibers in the monkey cervical spinal cord detected with diffusion-weighted magnetic resonance imaging

Neuroimage. 2011 Jun 1;56(3):923-9. doi: 10.1016/j.neuroimage.2011.02.043. Epub 2011 Feb 23.


Diffusion anisotropy monitored with diffusion-weighted magnetic resonance imaging (DWMRI) is a sensitive marker to monitor developmental or pathological microstructural changes in spinal cord. The white matter is often treated as a unidirectional axonal bundle but collateral fibers branching off the main spinal pathways contradicts this assumption and affects the diffusion anisotropy. It is the aim of this study to investigate to what extent collateral fibers are apparent in diffusion tensor data and if collaterals can be detected as individual fiber directions using crossing fiber detection techniques. We calculate the diffusion tensor and the persistent angular structure (PAS), a multi-fiber reconstruction technique, from high quality post mortem data of a perfusion-fixed vervet monkey cervical spinal cord sample and simulated crossing fiber data. Our results show that (i) cylindrical geometry in the white matter of the spinal cord is an invalid assumption due to collateral fibers. We also demonstrate that (ii) collateral fibers can be resolved as distinct peaks in the water diffusion propagator in white matter using multi-fiber models. Finally, we show that (iii) crossing fibers are mainly located laterally and increase towards the cervical enlargement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Afferent Pathways / cytology
  • Animals
  • Chlorocebus aethiops
  • Computer Simulation
  • Data Interpretation, Statistical
  • Diffusion Magnetic Resonance Imaging / methods*
  • Image Processing, Computer-Assisted
  • Nerve Fibers / physiology*
  • Perfusion
  • Pyramidal Tracts / cytology
  • Software
  • Spinal Cord / cytology*
  • Tissue Fixation