King's College London

Research portal

Fast acoustic wave sparsely activated localization microscopy: Ultrasound super-resolution using plane-wave activation of nanodroplets

Research output: Contribution to journalArticlepeer-review

Ge Zhang, Sevan Harput, Hanyu Hu, Kirsten Christensen-Jeffries, Jiaqi Zhu, Jemma Brown, Chee Hau Leow, Robert J. Eckersley, Christopher Dunsby, Meng Xing Tang

Original languageEnglish
Pages (from-to)1039-1046
JournalIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Issue number6
Early online date25 Mar 2019
Accepted/In press15 Mar 2019
E-pub ahead of print25 Mar 2019
PublishedJun 2019


King's Authors


Localization-based ultrasound super-resolution imaging using microbubble contrast agents and phase-change nanodroplets has been developed to visualize microvascular structures beyond the diffraction limit. However, the long data acquisition time makes the clinical translation more challenging. In this study, fast acoustic wave sparsely activated localization microscopy (fast-AWSALM) was developed to achieve super-resolved frames with subsecond temporal resolution, by using low-boiling-point octafluoropropane nanodroplets and high frame rate plane waves for activation, destruction, as well as imaging. Fast-AWSALM was demonstrated on an in vitro microvascular phantom to super-resolve structures that could not be resolved by conventional B-mode imaging. The effects of the temperature and mechanical index on fast-AWSALM were investigated. The experimental results show that subwavelength microstructures as small as 190μm were resolvable in 200 ms with plane-wave transmission at a center frequency of 3.5 MHz and a pulse repetition frequency of 5000 Hz. This is about a 3.5-fold reduction in point spread function full-width-half-maximum compared to that measured in the conventional B-mode, and two orders of magnitude faster than the recently reported AWSALM under a nonflow/very slow flow situations and other localization-based methods. Just as in AWSALM, fast-AWSALM does not require flow, as is required by current microbubble-based ultrasound super-resolution techniques. In conclusion, this study shows the promise of fast-AWSALM, a super-resolution ultrasound technique using nanodroplets, which can generate super-resolution images in milliseconds and does not require flow.

Download statistics

No data available

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454