Characterization of the diffusion process of different Gadolinium-based nanoparticles within the brain tissue after ultrasound induced Blood-Brain Barrier permeabilization

We present here a new method to study the diffusion process of Gadolinium-based MRI Contrast Agents within the brain extracellular space after ultrasound-induced Blood-Brain Barrier permeabilization. Four compounds were tested (MultiHance, Gadovist, Dotarem and AGuIX). By estimating the Free Diffusion Coefficients from in vitro studies, and the Apparent Diffusion Coefficients from in vivo experiments, an evaluation of the tortuosity (λ) in the right striatum of 11 Sprague-Dawley rats has been performed. The values of λ are in agreement with literature and demonstrate that the chosen permeabilization protocol maintains the integrity of brain tissue.