[The best in 2000 on heart imaging: "the transparent heart"].

Cardiac functional imaging focuses on three variables which complement each other: coronary perfusion reserve (during stress or after maximal vasodilation), myocardial viability (at cellular level) and ventricular contraction (endocardial motion or myocardial thickening). A combination of abnormal findings (location, size and severity) helps to characterise the myocardium in terms of normal, ischaemic, stunned, hibernating or necrosis. This functional information is then used to validate the morphological images of coronary lesions as seen on angiography, to assess the significance of a stenosis, to identify the culprit vessel in cases of multivessel disease, and to delineate the area at risk. "Non-invasive" techniques should no longer be considered only as screening methods with more sophisticated investigations in view, but should replace them at every step of patient management: at the time of diagnosis, with a "positive/negative" bayesian approach, before a therapeutic decision and during follow-up, especially when considering the prognosis of patients and risk stratification when the quantitation of functional abnormalities are major determinants.