Characterising high-risk plaque on cardiac CT

Coronary computed tomography angiography (CCTA) is a well-established and reliable non-invasive imaging modality that provides a comprehensive assessment of coronary artery anatomy and luminal stenosis due to atherosclerosis. Owing to advances in CCTA software and technology, the composition and morphology of coronary plaque can be accurately evaluated. Adverse features which identify plaque as being high-risk or 'vulnerable' can provide a personalised cardiovascular risk assessment over and above stenosis severity. High-risk plaque features on CCTA include spotty calcification, low attenuation plaque, positive remodelling and the napkin ring sign. However, it can be challenging to characterise high-risk plaque accurately on CCTA, and as such, education and experience are required. In this pictorial essay, a comprehensive visual guide to high-risk plaque features on CCTA is provided, with clear examples and challenging cases that highlight common pitfalls. It is important for expert readers to properly identify these features given their association with adverse outcomes and potential future implications on intensive goal-directed medical therapy.