Use of multislice CT for the evaluation of emergency room patients with chest pain: the so-called "triple rule-out".

Recent advances in computed tomography (CT) technology have made high resolution noninvasive coronary angiograms possible. Multiple studies involving over 2,000 patients have established that coronary CT angiography (CCTA) is highly accurate for delineation of the presence and severity of coronary atherosclerosis. The high negative predictive value (>95%) found in these studies suggests that CCTA is an attractive option for exclusion of coronary artery disease in properly selected emergency department patients with acute chest pain. CT is also a well established and accurate tool for the diagnosis of acute aortic dissection and pulmonary embolism. Recent technical developments now permit acquisition of well-opacified images of the coronary arteries, thoracic aorta and pulmonary arteries from a single CT scan. While this so called "triple-rule out" scan protocol can potentially exclude fatal causes of chest pain in all three vascular beds, the attendant higher radiation dose of this method precludes its routine use except when there is sufficient support for the diagnosis of either aortic dissection or pulmonary embolism. This article provides an overview of CCTA, and reviews the clinical evidence supporting the use of this technique for triage of patients with acute chest pain.