Characterization of atherosclerotic plaque with MARS imaging

This thesis illustrates the ability of MARS photon counting spectral CT (SPCCT) to identify and quantify intrinsic features of atherosclerotic plaque responsible for its rupture. Atherosclerosis is a disease in which plaque build-up in the arterial wall that can rupture and cause luminal occlusion leading to vascular insufficiency to the end organ. It is an ongoing degenerative process with grave consequences; necessitating timely identification of rupture prone plaque for risk stratification and mitigation of the disease. An estimated eight carotid endarterectomies are required to prevent one stroke in symptomatic patients with severe carotid artery stenosis whereas 30 carotid endarterectomies are required to prevent one stroke in asymptomatic patients. This limited ability to select patients at risk of stroke and the numbers need to treat with invasive and complex surgery that has an intrinsic risk of iatrogenic stroke has compelled to find more efficient imaging technology. Works presented in this thesis illustrate an effectiveness of MARS SPCCT in characterising different morphological components of atheroma, essential parameters to distinguish rupture prone plaque from stable one. Intrinsic characteristics of plaques were quantitatively and qualitatively evaluated in MARS images and compared with histopathological findings. Individual experiments explained in this thesis were designed to address research hypotheses while addressing possible sources of biases. Data analysis were done with suitable statistical tests. This research demonstrates the effectiveness of MARS SPCCT in atherosclerotic plaque imaging. It also shows the traslational potential of MARS SPCCT for clinical application helping clinician to choose appropriate protocol thereby improving patient care and treatment outcomes