Simultaneous and Robust Estimation of Cardiac-Induced 3D Brain Velocity and Diffusion Tensor Fields in the Human Brain

Motivation: Cardiac-induced brain pulsation is crucial for brain function, yet its measurement is challenging due to small displacements. Goal(s): The goal of this study is to develop a robust method to simultaneously measure both the cardiac-induced brain velocity vector and the corresponding diffusion tensor fields. Approach: We acquire DWIs with long diffusion times to enhance flow sensitivity and employ an outlier rejection method to eliminate inconsistent phase signals. Velocity vector and diffusion tensor fields were estimated from phase and magnitude images, respectively. Results: The high variability in the velocities across acquisitions was significantly reduced using our approach. The brain appeared still during late diastole. Impact: This study facilitates the measurement of intrinsic brain tissue motion with heartbeat compared to DENSE approaches, providing a new method for studying brain function.