Neuronavigation-guided transcranial histotripsy, results in a cadaveric model

Results from neuronavigation-guided transcranial histotripsy treatments in cadaveric models are presented. Histotripsy treatments were delivered transcranially to the brains of 3 cadavers (<96-h post-mortem) using a 30-cm diameter, 700-kHz, 360-element, transmit-receive capable transcranial histotripsy array. Pre-treatment CT and MRI scans of the head were acquired. A clinical neuronavigation system was used to coregister the histotripsy array with the cadaver head and guide treatments. Two-step aberration correction, combining pre-treatment CT-based correction and intra-procedure acoustic cavitation emission (ACE)-based correction, was employed to correct for skull-induced acoustic aberrations. Cavitation was generated at rates up to 200-Hz, and steered through 1-cm wide cubic targets in the brain. ACE signals were acquired throughout treatments using the array elements as receivers and used to localize cavitation and monitor treatment.Transcranial histotripsy was successfully applied to generate lesions in the cadaver brains. Two-step aberration correction resulted in significant improvements in focal quality and pressure. ACE-based cavitation localization could be achieved at rates up to 120-Hz. Neuronavigation-based coregistration/targeting errors ranged from 3 to 9-mm, but workflow issues have been identified and refinements have since reduced targeting errors to ≤1.5-mm. Changes in ACE signal features throughout treatments were observed to correlate with morphological observations of induced damage.