Coronary artery disease (CAD) remains one of the leading causes of morbidity and mortality worldwide. Moreover, the disease is reaching endemic proportions and will put an enormous strain on health care economics in the near future. Non-invasive testing is important to exclude CAD with a high certainty on the one hand, and to detect CAD with its functional consequences at an early stage, to guide optimal patient management, on the other hand. For these purposes, non-invasive imaging techniques have been developed and used extensively over the last years. Currently, the main focus of non-invasive imaging for diagnosis of CAD is twofold: (1) functional imaging, assessing the haemodynamic consequences of obstructive coronary artery disease; and (2) anatomical imaging, visualising non-invasively the coronary artery tree.

For functional imaging, nuclear cardiology, stress echocardiography, and magnetic resonance imaging (MRI) are used, whereas for anatomical imaging or non-invasive angiography, MRI, multislice CT (MSCT), and electron beam CT (EBCT) are used.

This manuscript will update the reader on the current status of non-invasive imaging, with a special focus on functional imaging versus anatomical imaging for the detection of CAD. The accuracies of the different imaging modalities are illustrated using pooled analyses of the available literature data when available.

FUNCTIONAL IMAGING

What information does functional imaging provide?

The hallmark of functional imaging is the detection of CAD by assessing the haemodynamic consequences of CAD rather than by direct visualisation of the coronary arteries. For this purpose, regional perfusion or wall motion abnormalities are induced (or worsened) during stress, reflecting the presence of stress induced ischaemia. Ischaemia induction is based on the principle that although resting myocardial blood flow in regions supplied by stenotic coronary arteries is preserved, the increased flow demand during stress cannot be met, resulting in a sequence of events referred to as “the ischaemic cascade”.¹ Initially perfusion abnormalities are …