Brain Pulsation Imaging Using Non-Balanced Steady-State Free Precession With 3D-EPI Readout

Area of Science:

• Medical Imaging
• Neuroimaging
• Biophysics

Background:

• Pulsatile motion of brain tissue and fluid is crucial for understanding neurological function and disease.
• Accurate quantification of this motion is challenging with existing MRI techniques.

Purpose of the Study:

• To present a novel, rapid MR imaging technique for visualizing and quantifying pulsatile displacement in brain tissue and fluid.
• To enable whole-brain coverage and detailed analysis of cardiac-cycle-induced motion.

Main Methods:

• Utilized natural phase-contrast in non-balanced steady-state free precession with tuned spoiler gradients.
• Employed efficient segmented 3D-EPI for whole-brain coverage (TR=0.15s).
• Incorporated motion-sensitive terms into extended phase graph theory and used simulations for optimization and calibration.

Main Results:

• Simulations indicated resolution of pulsatile displacements up to 1 mm.
• In vivo data aligned with simulation predictions, showing high precision (0.01 mm).
• The method provides detailed 3D visualization of pulsatile motion along orthogonal axes.

Conclusions:

• Brain Pulsation Imaging offers quantitative measurement of displacement vectors throughout the cardiac cycle.
• Achieves whole-brain coverage in 3-5 minutes, demonstrating robustness and clinical potential.