Assessment of subtle BBB disruption using Focused Ultrasound: comparison between the contrast agent exchange rate and the water exchange rate

Abstract

This study explores two different approachs of measuring subtle BBB disruption. To induce different levels of BBB disruption, we used a focused ultrasound (FUS) sonication with intravenously injected microbubbles with an animal model. Each animal underwent FUS procedure with different acoustic power levels. We compared the changes measured using DCE-MRI with Gadolinium-based contrast agent for volume transfer rate constant and Ferumoxytol-based ACE-MRI to measure transendotheliel water exchange rate. Our results suggest that both the water exchange rate and the contrast exchange rate show sensitive detection of subtle BBB disruption, which could shed light on understanding different permeability changes in BBB.