Improved reduction of motion artifacts in diffusion imaging using navigator echoes and velocity compensation

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Motion artifacts are a common problem in diffusion-weighted MRI, particularly in multishot imaging techniques.
• Existing navigator echo methods can reduce artifacts but often leave residual motion, limiting reliability.

Purpose of the Study:

• To investigate the efficacy of velocity-compensated diffusion sensitization combined with navigator echoes for reducing motion artifacts.
• To improve the reliability and clinical utility of motion artifact correction in diffusion-weighted MRI.

Main Methods:

• Applied a novel method for motion artifact quantification to brain images of healthy volunteers.
• Compared conventional (Stejskal-Tanner) and velocity-compensated gradient sensitization techniques with navigator echoes.
• Evaluated factors like pulsatile motion, b-factor, and signal-to-noise ratio.

Main Results:

• Velocity-compensated diffusion sensitization significantly reduced residual motion artifacts compared to conventional methods.
• The combined technique demonstrated improved image quality and reliability.
• Quantification method effectively assessed motion artifact reduction.

Conclusions:

• Velocity-compensated diffusion sensitization is a valuable addition to navigator echo techniques for motion artifact correction in diffusion-weighted MRI.
• This approach enhances the clinical applicability of diffusion MRI by improving image robustness.
• Further research can optimize parameters for maximum artifact reduction.