4.7-T diffusion tensor imaging of acute traumatic peripheral nerve injury

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Orthopedic Surgery

Background:

• Assessing microstructural nerve damage is challenging with current clinical methods.
• Diffusion tensor imaging (DTI) shows promise for detecting peripheral nerve crush injuries.
• No studies have utilized DTI for nerve transection injuries, a critical surgical condition.

Purpose of the Study:

• To evaluate the efficacy of high-resolution DTI in diagnosing and grading acute peripheral nerve transection injuries.
• To investigate DTI metrics for detecting microstructural changes in transected nerves.

Main Methods:

• Microsurgical sciatic nerve transection models were created in rats.
• Ex vivo high-resolution DTI was performed on harvested nerves at 4.7 T.
• Analysis included fractional anisotropy, eigenvalues, radial diffusivity, and diffusion tensor tractography.

Main Results:

• Fractional anisotropy was significantly reduced at transection sites.
• Minor eigenvalues and radial diffusivity were elevated, correlating negatively with injury severity.
• Diffusion tensor tractography revealed discontinuities and reduced tract counts.

Conclusions:

• High-resolution DTI is a viable tool for the acute diagnosis of peripheral nerve transection.
• DTI metrics can effectively grade the severity of traumatic nerve injuries.
• This technique holds potential for improving the management of nerve injuries.