Automatic Quantification of Local Plaque Thickness Differences as Assessed by Serial Coronary Computed Tomography Angiography Using Scan-Quality-Based Vessel-Specific Thresholds.

INTRODUCTION: The use of serial coronary computed tomography angiography (CCTA) allows for the early assessment of coronary plaque progression, a crucial factor in averting major adverse cardiac events (MACEs). Traditionally, serial CCTA is assessed using anatomical landmarks to match baseline and follow-up scans. Recently, a tool has been developed that allows for the automatic quantification of local plaque thickness differences in serial CCTA utilizing plaque contour delineation. The aim of this study was to determine thresholds of plaque thickness differences that define whether there is plaque progression and/or regression. These thresholds depend on the contrast-to-noise ratio (CNR). METHODS: Plaque thickness differences between two scans acquired at the same moment in time should always be zero. The negative and positive differences in plaque contour delineation in these scans were used along with the CNR in order to create calibration graphs on which a linear regression analysis was performed. This analysis was conducted on a cohort of 50 patients referred for a CCTA due to chest complaints. A total of 300 coronary vessels were analyzed. First, plaque contours were semi-automatically determined for all major epicardial coronary vessels. Second, manual drawings of seven regions of interest (ROIs) per scan were used to quantify the scan quality based on the CNR for each vessel. RESULTS: A linear regression analysis was performed on the CNR and negative and positive plaque contour delineation differences. Accounting for the standard error of the estimate, the linear regression analysis revealed that above 1.009 - 0.002 × CNR there is an increase in plaque thickness (progression), and below - 1.638 + 0.012 × CNR there is a decrease in plaque thickness (regression). CONCLUSION: This study demonstrates the feasibility of developing vessel-specific, quality-based thresholds for visualizing local plaque thickness differences evaluated by serial CCTA. These thresholds have the potential to facilitate the early detection of atherosclerosis progression.

Comprehensive plaque assessment with serial coronary CT angiography: translation to bedside.

The purpose of this review is to highlight the utility of comprehensive plaque assessment by serial coronary computed tomography angiography (CCTA) to understand atherosclerosis and its effect on cardiovascular risk stratification and management. CCTA is a validated, noninvasive imaging modality for coronary atherosclerotic plaque characterization. Numerous clinical trials have used approach of serial CCTA to demonstrate the potential benefits of multiple treatment strategies to reduce coronary plaque progression and its translation to benefits with cardiovascular outcomes. Serial CCTA trials for cardiovascular therapies combined with clinical outcome studies are providing mechanistic correlations of coronary atherogenesis and cardiovascular risk reduction, thereby establishing a new standard of care in addressing cardiac disease. Advancements in CCTA imaging and plaque analysis continue to expand the potential for CCTA in the evaluation of cardiovascular risk and targeted treatment of CAD.