Abstract #1738

Blood-Brain Barrier Disruption in Pigs by Transcranial Focused Ultrasound: Correlation of Cavitation Signals & MR Imaging for Treatment Monitoring

Yuexi Huang¹, Junho Song¹, Kullervo Hynynen^1,2

¹Imaging Research, Sunnybrook Research Institute, Toronto, ON, Canada; ²Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada

Magnetic resonance guided focused ultrasound (MRgFUS) has been demonstrated to reversibly disrupt the blood-brain barrier (BBB) for targeted drug delivery on small animal models. For large animals, however, a precise control of the location and pressure of the ultrasound focus is difficult due to the deflection and absorption of the ultrasound beam by the relatively thicker skull. In this study, a low frequency (230kHz) MRgFUS brain system was used to demonstrate the feasibility of localized BBB disruption in pigs without craniotomies. Cavitation signals from sonicated microbubbles were detected by hydrophones as a mean to monitor the treatment in real-time. The levels of cavitation signals at various acoustic powers showed good correlation to the levels of BBB disruption and tissue damage measured by T1-weighted and T2-weighted MR images.