Fig. 2.

BBB disruption in monkey 3 after targeting individual points with focused ultrasound and microbubbles. The disruption was demonstrated by delivery of an MR contrast agent (Gd-DPTA) that does not normally extravasate in the brain. (A) Sagittal contrast-enhanced MRI showing BBB disruption at six targeted locations (indicated by “+”) in the right hemisphere. The enhancement was contained to the targeted region except for small enhancement in a sulcus (circled) that was close to the most superficial location, which overlapped the lateral ventricle. Even though the same exposure level (314 kPa) was used for each sonication in this hemisphere, the size and magnitude of the different disruptions varied. (C) Axial view. Locations on left hemisphere were targeted at 223–273 kPa. (D) Axial T2-weighted image showing edema formation at the two targets in the thalamus (arrows). (E) T2*-weighted image showing hypointense spots at the thalamic targets as well as in a target in the putamen that was not evident in T2-weighted imaging. (scale bar: 1 cm