Three-dimensional quantitative magnetisation transfer imaging of the human brain

Area of Science:

• * Neuroimaging
• * Biophysical modeling
• * Magnetic Resonance Imaging (MRI)

Background:

• * Quantitative magnetisation transfer (MT) analysis relies on a two-pool model to assess proton pool properties.
• * High signal-to-noise ratio (SNR) is crucial for reliable parameter estimation in MT imaging.
• * Existing methods often require lengthy acquisition times or may confound analysis with excessive radio-frequency pulses.

Purpose of the Study:

• * To develop and validate an efficient 3D spoiled gradient acquisition for whole-brain quantitative MT analysis.
• * To achieve high SNR and accurate parameter estimation within a clinically acceptable timeframe.
• * To avoid confounding factors associated with slice-selective radio-frequency pulses.

Main Methods:

• * A novel 3D spoiled gradient acquisition sequence was implemented for whole-brain coverage.
• * The sequence was validated using post-mortem human brain tissue, comparing it against 2D protocols with varying SNRs.
• * Data from six healthy subjects were acquired and analyzed using the two-pool MT model.

Main Results:

• * The 3D acquisition achieved full brain coverage efficiently within a clinically acceptable time.
• * Image data fitted the two-pool model with negligible residual deviations.
• * Quantitative MT results were consistent with previous single-slice studies, yielding high-quality parametric maps.

Conclusions:

• * The developed 3D acquisition enables efficient and reliable whole-brain quantitative MT imaging.
• * The method provides accurate assessment of biophysical properties in different brain regions.
• * Further research is warranted to interpret the regional variations observed in quantitative MT parameters.