Fast 3D-EPI for characterization of CSF motion during the cardiac cycle.

Motivation: Individual variation in CSF dynamics may affect the efficiency of waste clearance from the brain. Goal(s): To develop a fast and sensitive MRI method for measurement of CSF motion during the cardiac cycle. Approach: Whole brain 3D-EPI at 3mm resolution and volTR=187ms was acquired at 7T for 94 seconds and retrospectively sorted into 20 cardiac phases based on pulse oximeter. Results: CSF dynamics was observed in all ventricles as well as in sub-arachnoid space, in addition to arterial pulsation. Both magnitude and phase pulsations were present in the 3 subjects acquired. Highest sensitivity to motion was observed along the phase-encoding direction. Impact: We show that fast 3D-EPI at 7T is very sensitive to the motion of CSF during the cardiac cycle. This method may be used to characterize CSF dynamics on individual patient level and aid understanding of brain diseases.