Trans-Stent B-Mode Ultrasound and Passive Cavitation Imaging.

Autor:	Haworth KJ; Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA. Electronic address: kevin.haworth@uc.edu., Raymond JL; Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA., Radhakrishnan K; Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA., Moody MR; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., Huang SL; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., Peng T; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., Shekhar H; Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA., Klegerman ME; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., Kim H; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., McPherson DD; Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA., Holland CK; Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Biomedical Engineering Program, University of Cincinnati, Cincinnati, Ohio, USA.
Jazyk:	angličtina
Zdroj:	Ultrasound in medicine & biology [Ultrasound Med Biol] 2016 Feb; Vol. 42 (2), pp. 518-27. Date of Electronic Publication: 2015 Nov 04.
DOI:	10.1016/j.ultrasmedbio.2015.08.014
Abstrakt:	Angioplasty and stenting of a stenosed artery enable acute restoration of blood flow. However, restenosis or a lack of re-endothelization can subsequently occur depending on the stent type. Cavitation-mediated drug delivery is a potential therapy for these conditions, but requires that particular types of cavitation be induced by ultrasound insonation. Because of the heterogeneity of tissue and stochastic nature of cavitation, feedback mechanisms are needed to determine whether the sustained bubble activity is induced. The objective of this study was to determine the feasibility of passive cavitation imaging through a metal stent in a flow phantom and an animal model. In this study, an endovascular stent was deployed in a flow phantom and in porcine femoral arteries. Fluorophore-labeled echogenic liposomes, a theragnostic ultrasound contrast agent, were injected proximal to the stent. Cavitation images were obtained by passively recording and beamforming the acoustic emissions from echogenic liposomes insonified with a low-frequency (500 kHz) transducer. In vitro experiments revealed that the signal-to-noise ratio for detecting stable cavitation activity through the stent was greater than 8 dB. The stent did not significantly reduce the signal-to-noise ratio. Trans-stent cavitation activity was also detected in vivo via passive cavitation imaging when echogenic liposomes were insonified by the 500-kHz transducer. When stable cavitation was detected, delivery of the fluorophore into the arterial wall was observed. Increased echogenicity within the stent was also observed when echogenic liposomes were administered. Thus, both B-mode ultrasound imaging and cavitation imaging are feasible in the presence of an endovascular stent in vivo. Demonstration of this capability supports future studies to monitor restenosis with contrast-enhanced ultrasound and pursue image-guided ultrasound-mediated drug delivery to inhibit restenosis. (Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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