Real-time correction by optical tracking with integrated geometric distortion correction for reducing motion...

Area of Science:

• Neuroimaging
• Medical Physics
• Biomedical Engineering

Background:

• Head motion is a significant source of artifacts in functional MRI (fMRI), limiting its utility in research and clinical applications.
• Existing real-time optical tracking corrects slice misalignment but may not address dynamic magnetic field nonuniformity.
• Phase Labeling for Additional Coordinate Encoding (PLACE) corrects geometric distortion using k-space data but requires integration for real-time applications.

Purpose of the Study:

• To integrate the Phase Labeling for Additional Coordinate Encoding (PLACE) technique into a real-time optical tracking system for fMRI.
• To evaluate the effectiveness of this integrated system in correcting motion-induced artifacts, including dynamic field nonuniformity.

Main Methods:

• Developed an approach combining real-time optical tracking with PLACE for volume-by-volume correction.
• Tested the integrated system on a moving tissue-equivalent phantom and during an fMRI finger-tapping task with induced head motion.
• Assessed artifact suppression by analyzing the corrected fMRI data.

Main Results:

• The integrated system effectively corrected artifacts arising from complex motion and dynamic field nonuniformity.
• Volume-by-volume correction demonstrated significant artifact suppression in both phantom and human fMRI experiments.
• The combined approach shows high efficacy in mitigating residual artifacts not addressed by optical tracking alone.

Conclusions:

• Integrating PLACE with real-time optical tracking offers a powerful solution for motion artifact correction in fMRI.
• This method holds potential for enhancing the reliability and expanding the applications of fMRI in neuroscience and clinical practice.
• The developed technique provides effective, real-time, volume-by-volume artifact suppression for improved fMRI data quality.