King's College London

Research portal

Optimal Control of SonoVue Microbubbles to Estimate Hydrostatic Pressure

Research output: Contribution to journalArticle

Original languageEnglish
JournalIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Early online date21 Oct 2019
DOIs
Publication statusE-pub ahead of print - 21 Oct 2019

Documents

King's Authors

Abstract

The measurement of cardiac and aortic pressures enable diagnostic insight into cardiac contractility and stiffness. However, these pressures are currently assessed invasively using pressure catheters. It may be possible to estimate these pressures less invasively by applying microbubble ultrasound contrast agents as pressure sensors. The aim of this study was to investigate the subharmonic response of the microbubble ultrasound contrast agent SonoVue (Bracco Spa, Milan, Italy) at physiological pressures using a static pressure phantom. A commercially available cell culture cassette with Luer connections was used as a static pressure chamber. SonoVue was added to the phantom, and radiofrequency data were recorded on the ULtrasound Advanced Open Platform (ULA-OP). The mean subharmonic amplitude over a 40% bandwidth was extracted at 0–200 mmHg hydrostatic pressures, across 1.7–7.0 MHz transmit frequencies and 3.5–100% maximum scanner acoustic output. The Rayleigh-Plesset equation for single bubble oscillations and additional hysteresis experiments were used to provide insight into the mechanisms underlying the subharmonic-pressure response of SonoVue. The subharmonic amplitude of SonoVue increased with hydrostatic pressure up to 50 mmHg across all transmit frequencies, and decreased thereafter. A decreasing microbubble surface tension may drive the initial increase in the subharmonic amplitude of SonoVue with hydrostatic pressure, while shell buckling and microbubble destruction may contribute to the subsequent decrease above 125 mmHg pressure. In conclusion, a practical operating regime that may be applied to estimate cardiac and aortic blood pressures from the subharmonic signal of SonoVue has been identified.

Download statistics

No data available

View graph of relations

© 2018 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454