Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) of atherosclerotic plaque angiogenesis

Abstract

Atherosclerosis is a progressive systemic disease of the large arteries characterized by the formation of plaques in the vessel wall. Despite our knowledge of its pathogenesis, many vulnerable plaques still remain undiagnosed while in their asymptomatic phase and manifest for the first time with dramatic clinical events, such as stroke or myocardial infarction. In recent years, it is becoming clearer that sudden clinical events do not necessarily correlate with the degree of luminal obstruction caused by lesions, but rather with plaque composition. In particular, the degree of plaque inflammation is important in the pathogenesis of atherosclerosis and is considered a good marker of high-risk/vulnerable plaques. The presence of inflammatory infiltrate and plaque neovascularization are both histological hallmarks of atherosclerotic plaque inflammation. Therefore, plaque angiogenesis represents an attractive target to try and identify asymptomatic high-risk lesions. Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) is a technique that has been used extensively in the past to study the vascularity of tumors and its changes following therapeutic intervention. Recently, delayed and dynamic contrast enhanced (CE) MRI have been proposed as non-invasive tools to study the extent of plaque neovascularization in animals and patients with atherosclerosis. In this review, we will provide a brief introduction on DCE-MRI acquisition and analysis techniques. We will follow this with a description of contrast enhanced MR methods for the detection and quantification of neovasculature in atherosclerosis, with an emphasis on DCE-MRI. Finally, we will examine the current limitations and challenges faced by DCE-MRI and briefly discuss its future applications in the context of atherosclerosis.