Empirical and Theoretical Characterization of the Diffusion Process of Different Gadolinium-Based Nanoparticles within the Brain Tissue after Ultrasound-Induced Permeabilization of the Blood-Brain Barrier

Figure 2

Experimental protocol for in vivo measurements: an ARFI sequence was used to detect the local acoustic intensity and choose the position of the BBB opening, indicated by the black arrow. This 2-minute acquisition was followed by a T₁-weighted MSME sequence and by the first T₁ map, acquired just before opening. One minute after the ultrasound opening session, the MRI contrast agent was injected. A T₁-weighted image was acquired to evaluate the goodness of the opening procedure. About two minutes after the CA injection, the diffusion process was followed over more than 1 hour, by acquiring several T₁ maps. At the end of each experimental session, a T₂-weighted RARE image was acquired to evaluate damages, such as hemorrhages and edema, due to ultrasound. All the images shown in this figure refer to acquisitions performed by using Gadovist.