Plaque imaging with CT—a comprehensive review on coronary CT angiography based risk assessment

Abstract

CT based technologies have evolved considerably in recent years. Coronary CT angiography (CTA) provides robust assessment of coronary artery disease (CAD). Early coronary CTA imaging-as a gate-keeper of invasive angiography-has focused on the presence of obstructive stenosis. Coronary CTA is currently the only non-invasive imaging modality for the evaluation of non-obstructive CAD, which has been shown to contribute to adverse cardiac events. Importantly, improved spatial resolution of CT scanners and novel image reconstruction algorithms enable the quantification and characterization of atherosclerotic plaques. State-of-the-art CT imaging can therefore reliably assess the extent of CAD and differentiate between various plaque features. Recent studies have demonstrated the incremental prognostic value of adverse plaque features over luminal stenosis. Comprehensive coronary plaque assessment holds potential to significantly improve individual risk assessment incorporating adverse plaque characteristics, the extent and severity of atherosclerotic plaque burden. As a result, several coronary CTA based composite risk scores have been proposed recently to determine patients at high risk for adverse events. Coronary CTA became a promising modality for the evaluation of functional significance of coronary lesions using CT derived fractional flow reserve (FFR-CT) and/or rest/dynamic myocardial CT perfusion. This could lead to substantial reduction in unnecessary invasive catheterization procedures and provide information on ischemic burden of CAD. Discordance between the degree of stenosis and ischemia has been recognized in clinical landmark trials using invasive FFR. Both lesion stenosis and composition are possibly related to myocardial ischemia. The evaluation of lesion-specific ischemia using combined functional and morphological plaque information could ultimately improve the diagnostic performance of CTA and thus patient care. In this review we aimed to summarize current evidence on comprehensive coronary artery plaque assessment using coronary CTA.

Coronary plaque characteristics and epicardial fat tissue in long term survivors of type 1 diabetes identified by coronary computed tomography angiography

“…Coronary computed tomography angiography (CCTA) has evolved as a non-invasive imaging technique for evaluation of stenoses in the coronary arteries, but it is also widely used in quantitative plaque assessments [6]. Evaluation of EAT volumes can also be performed on the same images [7].…”

Comprehensive coronary plaque assessment in patients with obstructive sleep apnea

“…However, recent studies demonstrated that coronary plaques are typically non‐calcified or partially calcified in OSA (Murphy et al., ; Sharma et al., ). In addition, CAC provides only an overall burden of calcified atherosclerotic plaques, and gives no information regarding non‐calcified plaques or the severity of coronary artery stenosis (Kolossvary, Szilveszter, Merkely, & Maurovich‐Horvat, ). The segment involvement score (SIS) measures the number of involved coronary segments and the segment stenosis score (SSS) weighs the number of involved segments by the degree of stenosis (Kolossvary et al., ).…”

“…In addition, CAC provides only an overall burden of calcified atherosclerotic plaques, and gives no information regarding non‐calcified plaques or the severity of coronary artery stenosis (Kolossvary, Szilveszter, Merkely, & Maurovich‐Horvat, ). The segment involvement score (SIS) measures the number of involved coronary segments and the segment stenosis score (SSS) weighs the number of involved segments by the degree of stenosis (Kolossvary et al., ). Unlike CAC, both of these parameters take into account calcified and non‐calcified plaques as well.…”

Implications of serial coronary computed tomography angiography in the evaluation of coronary plaque progression

“…Noncalcified plaques are further classified into fibrous, fibrofatty, or low attenuation based on Hounsfield unit. Noncalcified plaques can also be classified as homogenous or heterogenous in attenuation pattern [16]. Heterogenous plaques can be divided into with and without Napkin-ring sign (NRS).…”