Changes in Cerebrospinal Fluid Dynamics in the Whole Brain with Ultrasound Pulsed Stimulation: A Feasibility Study

Motivation: This study examines changes in cerebrospinal fluid (CSF) dynamics across the brain with low-intensity focused ultrasound (LIFU) applied to the transverse sinus to stimulate CSF flow. Goal(s): To visualize CSF dynamics across the rat brain following LIFU stimulation using contrast-enhanced MRI (CE-MRI) over a 24-hour period. Approach: Six SD rats received intrathecal contrast agent (into cisterna magna). CE-MRI scans were performed hourly, with LIFU stimulation during the first four hours (10 mins each). Voxel-wise analysis compared contrast dynamics with and without LIFU. Results: LIFU stimulation enhanced CSF dynamics, indicated by shorter time-to-peak and higher infusion rates across the brain compared to controls. Impact: This study highlights enhanced CSF dynamics over the whole brain in rats with the LIFU-induced stimulation, potentially facilitating waste clearance in glymphatic system.