Automated Coronary Plaque and Stenosis Assessment on Coronary CT Angiography: A Closer Look at Coronary Atherosclerosis

Abstract

Coronary artery disease remains the leading cause of morbidity and mortality in the United States and worldwide. Morphological changes in coronary vasculature can be detected by computed tomography angiography (CTA). Besides qualitative assessment, there has been an increased utilization of quantitative assessment of plaque and stenosis on CTA. For this purpose highly standardized methods have been developed, which are sufficiently reproducible on high quality datasets on a population level. This type of analysis could be potentially useful for not only follow-up of plaque progression but also for enhancing prediction of obstructive coronary arterial lesions and has been validated against current standards such as intra vascular ultrasound, optical coherence tomography, and near-infrared spectroscopy. Studies have demonstrated that types of plaque visualized on CTA have prognostic implications. However, classification of lesions as mild, moderate, or severe might not be enough to answer the clinical question of whether or not the lesion is causing ischemia. Fractional flow reserve computed tomography (CT) and transluminal attenuation gradient are new methods, which have shown great promise in assessment of severity and functional significance of stenosis. Similarly, CT stress testing for assessment of functional significance has been found to be feasible and studies are ongoing to evaluate the accuracy of CT stress perfusion. The promise of cardiovascular CT is to potentially become a comprehensive modality in patients with suspected CAD, by combining plaque imaging, stenosis detection, and the assessment of myocardial ischemia, to provide first-line evaluation in selected patient population.