[Role of noninvasive imaging in cardiology]

The technological advances of recent decades have produced a large armamentarium of cardiac noninvasive imaging tools for the diagnosis of coronary artery disease (CAD), including stress echocardiography, myocardial perfusion radionuclide imaging, cardiac computed tomography (cardiac CT) and cardiac magnetic resonance imaging. The high diagnostic accuracy of these techniques has been documented by single center and occasionally larger multicentric studies. Hence, the choice of the appropriate technique in a given patient is based upon the particular clinical scenario, the patient's clinical characteristics, local availability and expertise, and upon other factors such as costs, radiation and potential contrast agent toxicity. Cardiac CT is by nature an anatomical technique (much like invasive angiography) with a high negative predictive value, therefore it has established itself as a useful tool to rule out CAD in patients with low to intermediate pretest likelihood of CAD. The remaining techniques, on the other hand, are functional tests for the detection of myocardial ischemia and are suitable to improve risk stratification in patients with known CAD or at higher cardiovascular risk. By this means, non-invasive cardiac imaging is an accurate and established tool in the diagnostic algorithm for CAD, and a cost-effective gatekeeper of invasive angiography.