In vivo assessment of peripheral nerve regeneration by diffusion tensor imaging

✍ Scribed by Shinsuke Morisaki; Yuko Kawai; Masahiro Umeda; Mayumi Nishi; Ryo Oda; Hiroyoshi Fujiwara; Kei Yamada; Toshihiro Higuchi; Chuzo Tanaka; Mitsuhiro Kawata; Toshikazu Kubo

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 328 KB
• Volume: 33
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.22442

✦ Synopsis

Abstract

Purpose

To evaluate the sensitivity of diffusion tensor imaging (DTI) in assessing peripheral nerve regeneration in vivo. We assessed the changes in the DTI parameters and histological analyses after nerve injury to examine degeneration and regeneration in the rat sciatic nerves.

Materials and Methods

For magnetic resonance imaging (MRI), 16 rats were randomly divided into two groups: group P (permanently crushed; n = 7) and group T (temporally crushed; n = 9). Serial MRI of the right leg was performed before the operation, and then performed at the timepoints of 1, 2, 3, and 4 weeks after the crush injury. The changes in fractional anisotropy (FA), axial diffusivity (λ~∥~), and radial diffusivity (λ~⟂~) were quantified. For histological analyses, the number of axons and the myelinated axon areas were quantified.

Results

Decreased FA and increased λ~⟂~ were observed in the degenerative phase, and increased FA and decreased λ~⟂~ were observed in the regenerative phase. The changes in FA and λ~⟂~ were strongly correlated with histological changes, including axonal and myelin regeneration.

Conclusion

DTI parameters, especially λ~⟂~, can be good indicators for peripheral nerve regeneration and can be applied as noninvasive diagnostic tools for a variety of neurological diseases. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.