Positron emission tomography to assess the haemodynamics of the coronary circulation.

Positron emission tomography (PET) allows the non-invasive measurement of absolute myocardial blood flow (ml/min/g of myocardium) in man. This has made possible the measurement of myocardial blood flow and the coronary vasodilator reserve (an index of the ability of the coronary microcirculation to dilate) in healthy volunteers to establish the normal values and ranges of these parameters. This technique allows the assessment of the functional significance of epicardial coronary stenoses as well as the investigation of the function of the coronary microcirculation in patients with and without coronary artery disease.