Computed tomography angiography and other applications of computed tomography

Patients presenting with acute chest pain constitute a common and important diagnostic challenge. This has increased interest in using computed tomography for non-invasive visualization of coronary artery disease in patients presenting with acute chest pain to the emergency department; particularly the subset of patients who are suspected of having an acute coronary syndrome, but without typical electrocardiographic changes and with normal troponin levels at presentation. As a result of rapid developments in coronary computed tomography angiography technology, high diagnostic accuracies for excluding coronary artery disease can be obtained. It has been shown that these patients can be discharged safely. The accuracy for detecting a significant coronary artery stenosis is also high, but the presence of coronary artery atherosclerosis or stenosis does not imply necessarily that the cause of the chest pain is related to coronary artery disease. Moreover, the non-invasive detection of coronary artery disease by computed tomography has been shown to be related with an increased use of subsequent invasive coronary angiography and revascularization, and further studies are needed to define which patients benefit from invasive evaluation following coronary computed tomography angiography. Conversely, the implementation of coronary computed tomography angiography can significantly reduce the length of hospital stay, with a significant cost reduction. Additionally, computed tomography is an excellent modality in patients whose symptoms suggest other causes of acute chest pain such as aortic aneurysm, aortic dissection, or pulmonary embolism. Furthermore, the acquisition of the coronary arteries, thoracic aorta, and pulmonary arteries in a single computed tomography examination is feasible, allowing ‘triple rule-out’ (exclusion of aortic dissection, pulmonary embolism, and coronary artery disease). Finally, other applications, such as the evaluation of coronary artery plaque composition, myocardial function and perfusion, or fractional flow reserve, are currently being developed and may also become valuable in the setting of acute chest pain in the future.