pulse inversion

Enhanced detection of bubble emissions through the intact spine for monitoring ultrasound-mediated blood-spinal cord barrier opening

Author(s): Stecia-Marie Fletcher, Natalia Ogrodnik, Meaghan O’Reilly
Enhanced detection of bubble emissions through the intact spine for monitoring ultrasound-mediated blood-spinal cord barrier opening 170 177 IEEE Transactions on Biomedical Engineering (TBME)
Short burst, phase keying (SBPK) is a clinically relevant pulse scheme for focused ultrasound delivery to the spinal canal. We demonstrate that emissions from microbubbles exposed to these pulses can be detected through ex vivo human vertebrae, and that SBPK exposures can open the blood-spinal cord barrier (BSCB) in rats. Microbubbles were sonicated through ex vivo vertebrae and emissions were analyzed using short time Fourier analysis. Pulses were modified to include pulse inversion, which enhanced detection of acoustic signatures. In rats, opening was confirmed by MRI enhancement. Detection of the subharmonic was linked to tissue damage observed at histology. read more