Passive Cavitation Enhancement Mapping via an Ultrasound Dual-Mode phased array to monitor blood-brain barrier opening

• Published in: Journal of medical and biological engineering Vol. 42; no. 6; pp. 757 - 766
• Main Authors: Hoang, Trung Nguyen, Lin, Hsiang-Ching, Tsai, Chih-Hong, Jan, Cheng-Kai, Liu, Hao-Li
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2022; Springer Nature B.V
• Subjects: Biological Techniques; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedical Engineering/Biotechnology; Biomedicine; Blood-brain barrier; Cavitation; Central nervous system; Central nervous system diseases; Frequencies; Mapping; Neuroimaging; Original Article; Phased arrays; Quality assurance; Receiving; Regenerative Medicine/Tissue Engineering; Ultrasonic imaging; Ultrasonic testing; Ultrasound; Phased array; Focused ultrasound; Microbubble; Dual transmit/ received mode; Blood-brain barrier; Acoustic cavitation
• ISSN: 1609-0985; 2199-4757
• DOI: 10.1007/s40846-022-00735-2

Purpose Focused ultrasound with the presence of microbubbles has been shown to temporarily open the blood-brain barrier (BBB), which offers the potential to improve central nervous system disease treatment. Since BBB opening also highly correlates with the microbubble-induced stable cavitation, in this study, we aim to realize and implement the construction of cavitation-related passive mapping under the structure of a dual-mode phased array structure for the guidance of the focused ultrasound BBB-opening treatment. Methods A sparse distributed (48 out of a total of 256) receiving configuration was implemented to be functioned as dual-mode transmitting and receiving in the structure. The centered transmission locates at 400 kHz, whereas its 0.5x subharmonics (200 kHz), fundamental (400 kHz), 1.5x ultraharmonic (600 kHz), and 2nd harmonics (800 kHz) have been received and characterized. We demonstrated the capability of correlating the signal intensity with a wide range of microbubble concentrations in the in-vitro setup. In in-vivo verifications, a total of 9 animal experiments have been conducted to implement the passive cavitation mapping to correlate the imaging intensity with the occurrence of the outcome to induce blood-brain barrier opening. Results Ultraharmonics provided superior sensitivity and detectability to microbubble-related cavitation activity than the other selected frequency band, suggesting the potential in predicting BBB opening outcomes based on the passive image. Conclusion Cavitation mapping implemented by dual-mode ultrasound phased array is feasible and can provide assure the treatment quality in opening the blood-brain barrier in the brain.