Cardiac computed tomography

Recent developments in computed tomography (CT) technology permit imaging of the coronary arteries. Non-enhanced CT is used to perform coronary artery calcium scoring, which is useful to stratify the risk of future coronary events but does not allow assessment of stenosis. Contrast-enhanced CT enables angiographic evaluation of the coronary artery lumen. The high negative predictive value of coronary CT angiography (CTA) makes it a useful test to rule out the presence of significant coronary stenoses, especially in those patients with an intermediate pre-test likelihood of coronary artery disease. Coronary CTA also has potential to aid triage of patients with acute chest pain in the emergency department. Coronary artery bypass grafts can be reliably assessed using CT. Intracoronary stents are difficult to image due to artefacts caused by metal, often precluding detection of in-stent restenosis. There is emerging evidence of the ability of CT to characterize atherosclerotic plaque, which may help identify those plaques at most risk of rupture. The possibility of myocardial perfusion imaging using cardiac CT is the subject of current investigation.