Combining navigator and optical prospective motion correction for high-quality 500 μm resolution quantitative...

Area of Science:

• Neuroimaging
• Quantitative MRI
• Brain Microstructure Imaging

Background:

• High-resolution quantitative multi-parameter mapping offers non-invasive brain microstructure characterization.
• Physiological artifacts, such as head movement and respiration, limit the accuracy of these MRI techniques.
• Developing effective correction strategies is crucial for reliable brain imaging.

Purpose of the Study:

• To implement and evaluate corrections for rigid head movement and respiration-related B0-fluctuations in quantitative multi-parameter mapping.
• To assess the effectiveness of camera-based optical prospective motion correction (PMC) and FID navigator correction (NAVcor) separately and together.
• To evaluate these corrections in healthy volunteers, elderly volunteers, and dementia patients.

Main Methods:

• Implemented PMC and NAVcor in a multi-echo 3D gradient echo sequence for mapping proton density (PD), R1, and R2*.
• Evaluated corrections in young volunteers, then assessed NAVcor with PMC in elderly volunteers and dementia patients.
• Used spatial homogeneity in white matter (WM) and gray matter (GM) and scan-rescan reproducibility as quality metrics.

Main Results:

• NAVcor and PMC reduced artifacts, improving homogeneity and reproducibility of PD, R1, and R2* maps.
• In elderly participants, NAVcor decreased coefficient of variation by 14.7% (WM) and 11.9% (GM).
• PMC enhanced GM/WM contrast, particularly important in the more mobile elderly cohort.

Conclusions:

• Navigator correction and prospective motion correction significantly enhance the quality of quantitative MRI parameter maps.
• These corrections are particularly beneficial for less compliant populations, including elderly volunteers and dementia patients.
• Improved image quality facilitates more accurate non-invasive characterization of human brain microstructure.