Assessment of human brain motion using CSPAMM

Area of Science:

• Neuroimaging
• Biophysics
• Medical Physics

Background:

• Cranial and brain tissue displacement is a complex physiological process.
• Accurate quantification of this displacement is crucial for understanding brain dynamics and pathologies.
• Existing methods may lack the precision to capture subtle regional variations.

Purpose of the Study:

• To quantify periodic caudal brain tissue displacement using CSPAMM with HARP postprocessing.
• To assess the feasibility of distinguishing different brain regions based on displacement characteristics.
• To investigate the spatiotemporal dynamics of the pulse wave within the brain.

Main Methods:

• Utilized a CSPAMM tagging sequence with orthogonal tag-line preparation.
• Applied harmonic phase (HARP) postprocessing for tissue displacement mapping.
• Recruited 10 healthy volunteers for in vivo imaging.

Main Results:

• Successfully derived caudal displacement amplitude and time-to-peak for six brain regions.
• Observed significant differences in peak displacement, with the pons showing the highest values (0.18+/-0.02 mm).
• Demonstrated that displacement and time-to-peak measures can distinguish most brain regions, suggesting an occipital-to-frontal pulse wave propagation.

Conclusions:

• Direct quantification of periodic caudal brain tissue displacement is feasible with the CSPAMM-HARP method.
• The technique allows for differentiation of brain regions based on displacement amplitude and pulse wave timing.
• Findings support the proposed model of pulse wave propagation through the brain, originating from the brain stem.