Prospective motion correction for magnetic resonance spectroscopy using single camera Retro-Grate reflector optical...

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Spectroscopy

Background:

• Proton magnetic resonance spectroscopy (1H-MRS) is crucial for non-invasive brain metabolite quantification.
• Head motion during 1H-MRS scans introduces significant artifacts, compromising spectral quality and quantitative accuracy.
• Existing motion correction techniques often have limitations in real-time application and effectiveness.

Purpose of the Study:

• To develop and evaluate a prospective motion correction (PMC) technique for localized 1H-MRS.
• To assess the efficacy of a single-camera optical tracking system in mitigating motion-induced spectral artifacts.
• To improve the precision and reproducibility of metabolite ratio measurements in 1H-MRS.

Main Methods:

• Utilized a point-resolved spectroscopic sequence (PRESS) with a motion-tracking module and phase navigator at 3T.
• Employed a Retro-Grate Reflector (RGR) optical tracking system to monitor head motion in six degrees of freedom.
• Scanned five healthy participants performing predefined motion patterns during acquisition.

Main Results:

• Prospective motion correction effectively eliminated motion-induced increases in the total choline to total creatine (Cho/Cr) ratio caused by rotation (+1.1 ± 1.5% with correction vs. +14.6 ± 1.5% without).
• Correction significantly reduced artifacts from Z-translations, minimizing changes in Cho/Cr ratios (-2.2 ± 2.4% with correction vs. -13.2 ± 1.6% without).
• No significant changes were observed in other key metabolite ratios (NAA, Glx, mI) to creatine, indicating preserved spectral integrity.

Conclusions:

• Single-camera RGR-based prospective motion correction is effective for 1H-MRS.
• This method reduces spectral artifacts and quantitation errors, particularly in Cho/Cr ratios.
• The technique promises enhanced spectral quality and improved reproducibility in 1H-MRS studies.