Quantitative evaluation of myocardial blood flow with [13N]ammonia

The clinical need for diagnostic tools that accurately assess the functional status of the heart in patients with coronary artery disease and their response to therapeutic interventions has driven the development of noninvasive PET imaging techniques for measuring myocardial blood flow. A method for the estimation of myocardial blood flow based upon the pharmacokinetic properties of [13N]ammonia measured with a PET imaging system is described in this review. The formation of the [13N]ammonia tracer kinetic model for quantitative estimates of myocardial blood flow is presented. In addition, methods for coupling the tracer kinetic model with a simple geometric model representing the heart and bloodpool are described to minimize the bias introduced by the limited image resolution achieved in PET studies of the heart. Studies that have been performed to demonstrate the quantitative capabilities of the [13N]ammonia technique are also presented.