Imperial College London
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DrJamesChoi

Faculty of Engineering, Department of Bioengineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 1777j.choi Website

 
 
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Location

 

RSM 4.06Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Pouliopoulos:2016:10.1121/1.4964271,
author = {Pouliopoulos, A and Caiqin, L and Tinguely, M and Garbin, V and Tang, M and Choi, JJ},
doi = {10.1121/1.4964271},
journal = {Journal of the Acoustical Society of America},
title = {Rapid short-pulse sequences enhance the spatiotemporal uniformity of acoustically driven microbubble activity during flow conditions},
url = {http://dx.doi.org/10.1121/1.4964271},
volume = {140},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Despite the promise of microbubble-mediated focused ultrasound therapies, in vivo findings have revealed over-treated and under-treated regions distributed throughout the focal volume. This poor distribution cannot be improved by conventional pulse shapes and sequences, due to their limited ability to control acoustic cavitation dynamics within the ultrasonic focus. This paper describes the design of a rapid short-pulse (RaSP) sequence which is comprised of short pulses separated by μs off-time intervals. Improved acoustic cavitation distribution was based on the hypothesis that microbubbles can freely move during the pulse off-times. Flowing SonoVue® microbubbles (flow velocity: 10 mm/s) were sonicated with a 0.5 MHz focused ultrasound transducer using RaSP sequences (peak-rarefactional pressures: 146–900 kPa, pulse repetition frequency: 1.25 kHz, and pulse lengths: 5–50 cycles). The distribution of cavitation activity was evaluated using passive acoustic mapping. RaSP sequences generated uniform distributions within the focus in contrast to long pulses (50 000 cycles) that produced non-uniform distributions. Fast microbubble destruction occurred for long pulses, whereas microbubble activity was sustained for longer durations for shorter pulses. High-speed microscopy revealed increased mobility in the direction of flow during RaSP sonication. In conclusion, RaSP sequences produced spatiotemporally uniform cavitation distributions and could result in efficient therapies by spreading cavitation throughout the treatment area.
AU  - Pouliopoulos,A
AU  - Caiqin,L
AU  - Tinguely,M
AU  - Garbin,V
AU  - Tang,M
AU  - Choi,JJ
DO  - 10.1121/1.4964271
PY  - 2016///
SN  - 0001-4966
TI  - Rapid short-pulse sequences enhance the spatiotemporal uniformity of acoustically driven microbubble activity during flow conditions
T2  - Journal of the Acoustical Society of America
UR  - http://dx.doi.org/10.1121/1.4964271
UR  - http://hdl.handle.net/10044/1/40155
VL  - 140
ER  -
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