Insights into Atherosclerotic Cardiovascular Disease Using Multimodality Imaging

Abstract

This thesis investigates atherosclerosis as a systemic, multifactorial inflammatory disease by evaluating atherosclerotic burden through non-invasive multimodal imaging techniques, including computed tomography angiography (CTA), magnetic resonance imaging (MRI), and positron emission tomography (PET). Drawing on diverse international cohorts, the research characterises structural and physiological imaging biomarkers to serve as surrogate measures of plaque composition and biology across multiple vascular beds. The overarching aim is to demonstrate that integrating these complementary biomarkers improves patient-level risk stratification, identifies high risk vascular phenotypes, and provides greater precision for atherosclerosis assessment than traditional risk factor profiling alone.

A multimodality imaging framework is employed to uncover distinct, yet interconnected, pathophysiological insights. The research leverages CTA to quantify extracardiac plaque burden, revealing the limitations of standard modifiable cardiovascular risk factors (SMuRFs) in predicting true systemic disease extent. Additionally, it develops a simplified, reproducible dynamic contrast-enhanced MRI methodology that uses normalised signal intensity as a surrogate marker for carotid plaque neovascularisation, offering a reliable alternative to complex gadolinium kinetic modelling. Finally, dual-radiotracer PET/CT evaluations of arterial inflammation demonstrate that the distinct physiological processes driving atherosclerosis are only weakly correlated. Collectively, these studies underscore the additive diagnostic value of non-invasive multimodality imaging in atherosclerosis assessment. By capturing complex structural and biological insights not captured by conventional cardiovascular risk factor assessments or single-modality imaging approaches, this thesis establishes a comprehensive framework to complement existing risk stratification strategies for high risk atherosclerotic disease.