ABSTRACT
Coronary obstructions are generally described by location and severity. To describe the location of the lesion a standardized coronary segment classification is used. Despite the limitations of computed tomography (CT), in terms of the spatial resolution in relation to the small size of the coronary arteries, objective and reproducible stenosis quantification is possible with a certain degree of accuracy. Calcified deposits, as part of atherosclerotic disease, cause beam hardening and blooming artifacts that increase the apparent size of these high-density structures and complicate assessment of the adjacent coronary lumen. CT can detect atherosclerotic plaque in the coronary artery wall, which may or may not cause obstruction of the coronary artery lumen. Generally, coronary plaque identified by CT is classified as calcified, non-calcified, or mixed. The technical feasibility of CT coronary angiography compared with invasive coronary angiography has been validated extensively. Because of the high negative predictive value, CT is clinically used to rule out coronary artery disease.
