Characterization of focused intravascular transducer for vulnerable plaque diagnosis

Pao Yue-kong Library Electronic Theses Database

Characterization of focused intravascular transducer for vulnerable plaque diagnosis

 

Author: Xu, Yajie
Title: Characterization of focused intravascular transducer for vulnerable plaque diagnosis
Degree: M.Sc.
Year: 2016
Subject: Ultrasound transducers.
Intravascular ultrasonography.
Arteriosclerosis -- diagnosis.
Hong Kong Polytechnic University -- Dissertations
Department: Interdisciplinary Division of Biomedical Engineering
Pages: ix, 52 pages : color illustrations
Language: English
InnoPac Record: http://library.polyu.edu.hk/record=b2894537
URI: http://theses.lib.polyu.edu.hk/handle/200/8498
Abstract: An estimated more than 19 million people dies annually due to the atherosclerotic cardiovascular disease. Among these deaths, the disease of the arteries accounts for the main part and the formation of a plaque in the walls of arteries could play a key role in risking patient life. In clinical, a life threatening stage of the atherosclerotic cardiovascular disease is the formation of vulnerable plaque which are characterized by large lipid pool, heavy macrophage, thin fibrous collagen-rich cap. Therefore, the vulnerable plaque could rupture easily and lead to inflammation, calcification and hemorrhage. Currently, the artery disease is clinically conducted by the gold standard technique X-Ray angiography. This method can reveal luminal diameter and provide the dimension of stenosis. But this method cannot image the vessel wall and give detailed information about the composition of the atherosclerotic plaque, thus the main features of the atherosclerotic disease such as the lipid rich plaque cannot be seen. Intravascular ultrasound (IVUS) is a new technique to the arterial vascular wall imaging. This technique can execute real-time and direct imaging of the atheroma and give cross-sectional, tomographic perspective of the vessel wall and atherosclerotic disease. In addition, this method can also detect unrecognized disease and uncertain severity of lesions by X-Ray angiography. More importantly, IVUS can delineate the thickness and echogenicity of vessel wall structures. In addition, the spectra information of the RF signal can facilitate the reorganization of atheroma. However, the histopathological information of the atherosclerotic cardiovascular disease is limited due to the low axial resolutions and lateral resolutions of current commercial IVUS transducer. In order to overcome these drawbacks, the focused transducer fabricated by mechanical dimpling method could be used. In order to prove the effectiveness of the focused transducer, pulse-echo experiment, wire phantom and zebra fish model were conducted. In the pulse-echo experiment, the focused transducer with 40MHz center frequency showed a broader bandwidth and higher sensitivity than the plane one. Additionally, in the B-mode experiment by using the wire phantom, focused transducer demonstrated a better axial resolution and lateral resolution. Finally, the focused transducer also has been proved have the ability to distinguish the cornea and iris of the zebra fish eye. Therefore, the IVUS system with focused transducer is a promising imaging technique to detect and diagnosis the atherosclerotic cardiovascular disease with vulnerable plaque.

Files in this item

Files Size Format
b28945372.pdf 10.19Mb PDF
Copyright Undertaking
As a bona fide Library user, I declare that:
  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

     

Quick Search

Browse

More Information