Date of Award
2008
Degree Type
Thesis
Degree Name
Doctor of Philosophy
Program
Biomedical Engineering
Supervisor
Dr. Aaron Fenster
Second Advisor
Dr. Grace Parraga
Third Advisor
Dr. J. David Spence
Abstract
Atherosclerosis, the build-up of plaque within the arterial wall, at the carotid arteries may lead to stroke. Quantitative measurements of the progression/regression of carotid plaque are important in monitoring patients and evaluating new treatment options. Many researchers have investigated the use of 3D ultrasound (US) to quantify plaque or vessel wall volume. However, few studies have quantified the spatial distribution of plaque in the carotid arteries. Although plaque volume measurements are useful for serial monitoring of patients, information on the location where plaque changes would facilitate a deeper understanding of natural disease progression and allow testing of hypotheses about treatment effects. This thesis describes the development and application of a method for analyzing changes in vessel-wall- plus-plaque thickness (VWT) using 3D US. VWT was obtained by computing the distance between the carotid wall and lumen surfaces on a point-by-point basis. In order to monitor VWT progression of patients, VWT-Change was computed by comparing VWT maps of the same, patient obtained at two time points. Experimental results show that the proposed technique can be used to quantify and display VWT- Change at each point on the arterial wall, and the results are consistent with those produced in the plaque volume monitoring study performed for the same group of patients. Although the 3D VWT-Change maps provide rich information on the spatial distribution of plaque change, a flattened map representation of the 3D maps is . preferable for analysis. The flattened representation allows the analysis of 3D maps in a single view, eliminating the need to study the 3D maps from multiple angles in an investigation, thereby allowing easy comparison of the locations of plaque progression/regression shown on 2D maps obtained for the same patient at different time points. In addition to quantifying VWT, a method is introduced to quantify the local irregularity of lumen surfaces. Results show that this algorithm can be used to identify the location of ulcers of the carotid artery.
Recommended Citation
Chiu, Bernard, "Quantification of Carotid Atherosclerosis using 3-dimensional Ultrasound Images" (2008). Digitized Theses. 4740.
https://ir.lib.uwo.ca/digitizedtheses/4740