Cardiac computed tomography: diagnostic utility and integration in clinical practice.

Cardiac applications of computed tomography (CT) is a rapidly growing diagnostic area because of the ability to visualize plaque burden (coronary artery calcification [CAC]) and luminal obstruction (computed tomographic angiography [CTA]) noninvasively. Coronary artery calcification has been validated in over 1,000 studies over the last 20 years, primarily with electron beam tomography. Studies demonstrate several indications that could aid physicians in the management of symptomatic and asymptomatic patients. Determining that a symptomatic patient has no CAC is associated with both a lower risk of an abnormal nuclear study and angiographic obstruction. The ability to detect subclinical atherosclerosis (CAC) with minimal radiation and no contrast makes this an attractive method for risk stratification. New studies demonstrate a 10-fold risk of cardiovascular events with increasing amounts of coronary calcification. The invasive nature, expense, and risk resulting from invasive angiography have been instrumental in encouraging the development of new diagnostic methods that allow the coronary arteries to be visualized noninvasively. Multislice CT, with its advanced spatial and temporal resolution, has opened up new possibilities in the imaging of the heart and major vessels of the chest, including the coronary arteries. The last decade has seen great strides in the field of cardiac imaging, particularly in the ability to visualize the coronary lumen with sufficient diagnostic accuracy. Possessing that qualification, CTA is now being used increasingly in clinical practice. As a result of having high spatial and improved temporal resolutions, this imaging modality not only allows branches of the coronary artery to be evaluated, but also allows simultaneous analysis of other cardiac structures, making it extremely useful for other cardiac applications. This paper reviews the diagnostic utility and limitations of cardiac CT and how it could be integrated into clinical practice.