An Acoustic Measurement Library for Non-Invasive Trans-Rodent Skull Ultrasonic Focusing at High Frequency

Rahimi, Saba; Jones, Ryan M.; Hynynen, Kullervo

doi:10.1109/tbme.2021.3138352

Cited by 1 publication

(1 citation statement)

References 44 publications

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“…In our in vivo experiment we did not implement any aberrations corrections, which may have resulted in lack of accurate passive acoustic maps. This issue can be overcome by applying aberration correction on both transmit and receive beamforming 36 , 38 , especially when transducers are centered at high frequency with a comparable focus size as ours 40 , 41 . Additionally, we can lower the frequency of our imaging transducer such that it is closer to resonance frequency of MBs.…”

Section: Discussionmentioning

confidence: 99%

Guiding and monitoring focused ultrasound mediated blood–brain barrier opening in rats using power Doppler imaging and passive acoustic mapping

Singh

Kusunose

Phipps

et al. 2022

Sci Rep

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The blood–brain barrier (BBB) prevents harmful toxins from entering brain but can also inhibit therapeutic molecules designed to treat neurodegenerative diseases. Focused ultrasound (FUS) combined with microbubbles can enhance permeability of BBB and is often performed under MRI guidance. We present an all-ultrasound system capable of targeting desired regions to open BBB with millimeter-scale accuracy in two dimensions based on Doppler images. We registered imaging coordinates to FUS coordinates with target registration error of 0.6 ± 0.3 mm and used the system to target microbubbles flowing in cellulose tube in two in vitro scenarios (agarose-embedded and through a rat skull), while receiving echoes on imaging transducer. We created passive acoustic maps from received echoes and found error between intended location in imaging plane and location of pixel with maximum intensity after passive acoustic maps reconstruction to be within 2 mm in 5/6 cases. We validated ultrasound-guided procedure in three in vivo rat brains by delivering MRI contrast agent to cortical regions of rat brains after BBB opening. Landmark-based registration of vascular maps created with MRI and Doppler ultrasound revealed BBB opening inside the intended focus with targeting accuracy within 1.5 mm. Combined use of power Doppler imaging with passive acoustic mapping demonstrates an ultrasound-based solution to guide focused ultrasound with high precision in rodents.

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