Quantitative measurement of regional myocardial blood flow in patients with coronary artery disease by intravenous injection of 13N-ammonia in positron emission tomography.

Measurement of myocardial blood flow with 13N-ammonia, a technique previously employed successfully in animal experiments, was introduced into clinical use to study patients with coronary artery disease. This advance has become possible by the development of a high resolution gated scan positron emission tomographic (PET) scanner equipped with a real time decay correction mechanism, HEADTOME-IV. The information obtainable includes myocardial size and wall motion as well as the absolute quantity of blood flow in various myocardial regions. The technique is simple but requires continuous arterial blood withdrawal for calculation of the arterial input function time integral. The alternative to this technique, i.e. the computation of intra left ventricular blood pool activity by PET is also discussed.