Improving Cardiovascular Risk Assessment with CT Coronary Angiography and Myocardial CT Perfusion
type: CreativeWork
description: Accurate assessments of coronary atherosclerosis, calcification and myocardial perfusion are necessary to determine future cardiovascular risk in various clinical settings. CT coronary angiography (CTCA) and myocardial CT perfusion (CTP) are promising techniques for the assessment of these factors. This thesis is comprised of several projects which explore refinements and new techniques aimed at improving diagnosis and risk stratification by CTCA. In order to improve CT methodology, coronary motion in mid-diastole was examined utilizing both high temporal-resolution tissue Doppler imaging and CT. The period of mid-diastole was found to occur relatively later in the cardiac cycle with increasing heart rate. The study demonstrated the importance of heart rate control and precise timing in cardiac imaging. The coronary calcium score allows quantification of cardiovascular risk in asymptomatic patients. A new method of calculating the coronary calcium score from contrast-enhanced CTCA was developed and assessed. Within the validation cohort, the calculated calcium score was highly correlated with the measured calcium score with minimal bias. Coronary calcium may also affect accurate assessment of the degree and extent of coronary disease at CTCA. We examined CTCA findings in patients with a calcium score of >600. Downstream investigations, cardiovascular events, revascularization and mortality were recorded. It was shown that while CT in this setting has reduced specificity, the sensitivity to clinically significant disease appears to be preserved. CTP may be used to assess the functional significance of coronary disease. Utilizing a validated CT and MRI compatible perfusion phantom, the sensitivity of CTP and magnetic resonance perfusion were directly compared under various conditions. Despite the distinct physical basis of each technique, the sensitivity and signal-to-noise ratios were similar, supporting the further development of CTP techniques. Image noise is a maj…
abstract: Accurate assessments of coronary atherosclerosis, calcification and myocardial perfusion are necessary to determine future cardiovascular risk in various clinical settings. CT coronary angiography (CTCA) and myocardial CT perfusion (CTP) are promising techniques for the assessment of these factors. This thesis is comprised of several projects which explore refinements and new techniques aimed at improving diagnosis and risk stratification by CTCA. In order to improve CT methodology, coronary motion in mid-diastole was examined utilizing both high temporal-resolution tissue Doppler imaging and CT. The period of mid-diastole was found to occur relatively later in the cardiac cycle with increasing heart rate. The study demonstrated the importance of heart rate control and precise timing in cardiac imaging. The coronary calcium score allows quantification of cardiovascular risk in asymptomatic patients. A new method of calculating the coronary calcium score from contrast-enhanced CTCA was developed and assessed. Within the validation cohort, the calculated calcium score was highly correlated with the measured calcium score with minimal bias. Coronary calcium may also affect accurate assessment of the degree and extent of coronary disease at CTCA. We examined CTCA findings in patients with a calcium score of >600. Downstream investigations, cardiovascular events, revascularization and mortality were recorded. It was shown that while CT in this setting has reduced specificity, the sensitivity to clinically significant disease appears to be preserved. CTP may be used to assess the functional significance of coronary disease. Utilizing a validated CT and MRI compatible perfusion phantom, the sensitivity of CTP and magnetic resonance perfusion were directly compared under various conditions. Despite the distinct physical basis of each technique, the sensitivity and signal-to-noise ratios were similar, supporting the further development of CTP techniques. Image noise is a maj…
author: Otton, James
language: EN
keywords: Cardiac MRI, Computed tomography, Cardiac CT, Myocardial perfusion, Calcium score
license: https://purl.org/coar/access_right/c_abf2
license: https://creativecommons.org/licenses/by-nc-nd/3.0/au/
date published: 2013
date modified: 2026-07-24T05:32:00Z
provider: University of New South Wales
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: UNSW, Sydney

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1959.4/53339

PropertyValue
property ID: DOI
value: 10.26190/unsworks/16684