Three-Dimensional In vivo Magnetic Resonance Imaging (MRI) of Mouse Facial Nerve Regeneration

Frontiers in Neurology, 2019 · DOI: 10.3389/fneur.2019.00310 · Published: April 2, 2019

Simple Explanation

This study focuses on using MRI to visualize and monitor the regeneration of the facial nerve in mice after injury, without using contrast agents. The researchers developed a high-resolution MRI protocol to image even very small nerves, like the mouse facial nerve, over a period of three weeks after injury. The MRI scans showed changes in the nerve, such as increased signal intensity and size, at the injury site, which correlated with the recovery of nerve function.

Study Duration
3 weeks
Participants
Seven male adult wild-type C57BL/6J mice aged 13–14 weeks
Evidence Level
Not specified

Key Findings

  • 1
    Nerve injury caused hyperintense signal in T2-weighted images, and an increase in nerve size of the proximal and distal nerve stumps were observed.
  • 2
    Longitudinal MR representation of facial nerve lesions correlated well with physiological recovery of nerve function by quantifying whisker movement.
  • 3
    A novel protocol in rodents allows for non-invasive, non-contrast agent enhanced, high-resolution MR imaging of small peripheral nerves longitudinally over several weeks.

Research Summary

The study establishes an MRI protocol in mice to monitor the regeneration of small nerves without contrast agents, focusing on the facial nerve. MRI scans revealed nerve hyperintensity after injury, which was correlated with the accumulation of fibrotic material and immune/Schwann cells in the nerve areas. The developed MRI protocol allows for longitudinal high-resolution imaging of small nerve branches at identical positions in the same animal over several weeks.

Practical Implications

Diagnostic Tool

MRI can be used as a diagnostic tool for peripheral nerve injuries.

Post-Surgery Monitoring

MRI can be used as a follow-up tool to monitor peripheral nerve injuries in humans.

Clinical Translation

Novel high-resolution MRI protocols established in a rodent model system bear immediate translational potential to the clinics.

Study Limitations

  • 1
    The study only analyzed 3 weeks after injury.
  • 2
    Molecular nature and specificity of MRI signal changes are debated.
  • 3
    Functional nerve regeneration was far from complete.

Your Feedback

Was this summary helpful?