Assessing atherosclerotic burden with CT

Computed tomography (CT) has long been used for the evaluation of both normal and pathologic human anatomy. In the setting of atherosclerosis (AS) and cardiovascular disease (CVD), CT angiography has a well-established role for the detection of luminal stenoses and aneurysms in various vascular territories such as the aorta, carotid, renal, and lower-extremity arteries. Although of indisputable value in clinical practice, such findings reflect an already advanced stage of the disease. The atherosclerotic changes of the arterial wall in fact commence much earlier, as microscopic lesions progressing slowly into macroscopic plaques that often grow eccentrically without compromising the vessel lumen.¹ Reliance on changes in luminal caliber is therefore insufficient for estimating the extent and severity of atherosclerotic burden. In fact, clinical events are often caused by acute complications (rupture and thrombosis) of specific plaques that may not produce a significant luminal narrowing, particularly in the coronary tree.² Because AS is a systemic disorder involving multiple vascular territories, it is important not to restrict the evaluation to a single arterial system. The visualization of the coronary arteries with CT has, however, been traditionally limited by their continuous motion from both cardiac and respiratory origins.