MICROBUBBLE VOID IMAGING: A NON-INVASIVE TECHNIQUE FOR FLOW VISUALISATION AND QUANTIFICATION OF MIXING IN LARGE VESSELS USING PLANE WAVE ULTRASOUND AND CONTROLLED MICROBUBBLE CONTRAST AGENT DESTRUCTION
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Date: 
Tuesday, June 23, 2015
Abstract: 

There is increasing recognition of the influence of the flow field on the physiology of blood vessels and their development of pathology. Preliminary work is reported on a novel non-invasive technique, microbubble void imaging, which is based on ultrasound and controlled destruction of microbubble contrast agents, permitting flow visualisation and quantification of flow-induced mixing in large vessels. The generation of microbubble voids can be controlled both spatially and temporally using ultrasound parameters within the safety limits. Three different model vessel geometries—straight, planar-curved and helical—with known effects on the flow field and mixing were chosen to evaluate the technique. A high-frame-rate ultrasound system with plane wave transmission was used to acquire the contrast-enhanced ultrasound images, and an entropy measure was calculated to quantify mixing. The experimental results were cross-compared between the different geometries and with computational fluid dynamics. The results indicated that the technique is able to quantify the degree of mixing within the different con- figurations, with a helical geometry generating the greatest mixing, and a straight geometry, the lowest. There is a high level of concordance between the computational fluid dynamics and experimental results. The technique could also serve as a flow visualisation tool. (E-mail: mengxing.tang@imperial.ac.uk) 2015 World Federation for Ultrasound in Medicine & Biology. Key Words: Contrast-enhanced ultrasound, Microbubble contrast agents, Mixing, Flow indicator, Microbubble void imaging, High-frame-rate plane wave imaging.

Author Name: 
CHEE HAU LEOW
FRANCESCO IORI
RICHARD CORBETT
NEILL DUNCAN
COLIN CARO
PETER VINCENT
MENG-XING TANG
Author Company: 
Imperial College, London, UK
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