Sixty-four-slice computed tomographic coronary angiography: will the "triple rule out" change chest pain evaluation in the ED?

Sixty-four-slice computed tomographic (CT) coronary angiography is a new technique for the noninvasive visualization of the coronary arteries. It enables noninvasive detection of coronary plaque and determination of severity without instrumentation of the heart. Although not yet commonly used in the emergency department setting, it stands poised to dramatically change the way that patients with chest pain are evaluated. In addition to evaluation of the coronary arteries, CT angiography has long been used to evaluate patients for other dangerous causes of chest pain such as aortic dissection and pulmonary embolus. Although these new scanners excel at all of these diagnostic modalities, the true excitement is in the possibility of combining several different protocols into one, allowing for multiple causes of chest pain to be "ruled out" simultaneously. This article describes the current state of the art of cardiac CT, current state of research, and current areas of controversy.