What is the current role of electron beam computed tomography in coronary imaging?

Abstract

Electron beam computed tomography (EBCT) has emerged as a powerful means to examine and quantitate cardiovascular anatomy, function, and flow in patients presenting with a variety of diseases of the heart, coronary arteries, pericardium and great vessels. This brief discussion is focused on the developing use of EBCT to image the coronary arteries. There are currently two main areas of interest, i.e., the quantification of coronary calcium by EBCT and the use of peripheral contrast injections for coronary luminal opacification (intravenous EBCT coronary angiography). The amount of coronary calcium as determined by EBCT has been shown to be representative of coronary atherosclerotic plaque burden and thus offers a non-invasive approach to the delineation of coronary artery disease. In several thousands patients followed over one through 5 years, quantities of coronary calcium have been demonstrated to predict cardiovascular events and related mortality. Individuals with large amounts of coronary calcium have a high likelihood of at least one obstructive coronary lesion, require strict measures regarding modifiable risk factors, and may additionally be considered for further evaluations of potential myocardial ischemia. Intravenous EBCT coronary angiography has been performed by several independent groups of investigators and has yielded highly reproducible results. The proximal segments of the major coronary arteries are reliably visualized. High negative predictive values suggest that this technique may be of value for ruling out significant disease in patients undergoing clinical evaluation for obstructive versus non-obstructive coronary artery disease. As is true for any cardiac imaging modality, EBCT should be analyzed in the context of the patient’s history and symptoms.