Isotropic resolution diffusion tensor imaging of lumbosacral and sciatic nerves using a phase-corrected...

Area of Science:

• Medical Imaging
• Neuroimaging
• Diffusion Tensor Imaging

Background:

• Diffusion Tensor Imaging (DTI) is crucial for assessing nerve integrity.
• Conventional DTI methods can be susceptible to motion and phase errors, leading to image artifacts and inaccurate quantification.
• Developing robust DTI techniques for peripheral nerves, such as the sciatic nerve, is essential for clinical diagnosis.

Purpose of the Study:

• To implement and evaluate a phase-navigated diffusion-prepared (DP) 3D turbo spin echo (TSE) acquisition for in vivo isotropic-resolution DTI of lumbosacral and sciatic nerves.
• To assess the impact of intershot phase-error correction on image quality and diffusion quantification.
• To investigate the robustness of the proposed method against motion-induced artifacts.

Main Methods:

• A phase-navigated DP 3D TSE sequence with magnitude stabilizers was employed for DTI acquisition.
• Phase navigation was incorporated before readout to correct motion-induced phase errors.
• In vivo DTI of lower back nerves was performed in 13 subjects, comparing the proposed 3D TSE method with single-shot echo planar imaging (ss-EPI).

Main Results:

• Non-phase-corrected 3D TSE DTI showed artifacts and overestimated mean diffusivity (MD) in the sciatic nerve (2.06 ± 0.45).
• Phase correction significantly reduced DTI parameters (MD = 1.73 ± 0.26) compared to non-corrected data (P ≤ 0.001).
• Phase-corrected 3D TSE DTI parameters closely agreed with ss-EPI DTI parameters (MD = 1.62 ± 0.21).

Conclusions:

• Phase-corrected DP 3D TSE enables distortion-free, isotropic DTI of lower back nerves.
• The technique demonstrates robustness against motion-induced artifacts and DTI quantification errors.
• This method enhances the reliability of diffusion imaging for peripheral nerve assessment.