Cardiovascular magnetic resonance of the arterial wall in early atherosclerosis

Abstract

BACKGROUND The paradigm that atherosclerosis is just luminal stenosis has now been superseded by work illustrating that it is a complex interplay of inflammatory processes with vessel wall remodelling. Non-invasive cardiovascular magnetic resonance (CMR) techniques can play an important role in providing quantitative volumetric assessment of atherosclerotic plaque burden, identifying early atherosclerotic changes and determining the composition of plaque constituents. We aimed to demonstrate how bulk motion artefacts can potentially lead to deleterious quality image, how novel methods of bulk motion correction can provide better image quality, to use a new CMR approach to characterise plaque, and apply the technique in a novel "at risk" population through imaging of the carotid arteries. METHODS AND RESULTS We used a novel method of detecting swallowing and established that swallowing during image acquisition can have a profound adverse effect on image quality. We showed that application of an accept or reject algorithm which deletes data acquired during swallowing, improves image quality. Respiratory movement of the carotid arteries has a similar detrimental effect on image quality but to a lesser extent and is variable between individuals. We demonstrated that the use of an ultra-short echo time (UTE) sequence can detect areas of calcification within plaque in ex vivo carotid artery specimens and correlated this with computerised tomography and histological data. Finally, we showed there was a positive effect on early atherosclerosis in patients with Behçet"s Disease treated with interferon-alpha. We showed that this may be related to stimulation of homeostatic IgM antibodies with improved clearance of biologically active lipids which have undergone oxidation and improvement in endothelial function. CONCLUSIONS Through sequence development, we have shown how bulk motion artefact can be overcome to improve image quality of carotid artery wall imaging, and how we can further characterise plaque constituents. Furthermore, we demonstrate how CMR of the vessel wall can be applied in clinical trials to assess early atherosclerotic plaque burden, with novel results of the improvement in atherosclerosis using interferon, which has not previously been described.