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In this issue of the Journal of Nuclear Cardiology, Pieper et al. report on their experience of an N13-ammonia compact superconducting production system for positron emission tomography myocardial perfusion imaging (PET MPI). Currently the production of N13ammonia, an alternate FDA approved PET tracer to rubidium-82, requires the presence of an on-site or very close proximity cyclotron. This necessity, because of the cost and complexity involved, severely limits the feasibility of this radiotracer. This new system, in which this is the first clinical report, holds promise to considerably improve availability of N13-ammonia to many more office and hospital-based practices. Cardiac PET myocardial perfusion imaging has been gaining momentum in the cardiac imaging arena, primarily based upon its superior characteristics in comparison with other non-invasive modalities. In a recent joint Position Statement, the American Society of Nuclear Cardiology and the Society of Nuclear Medicine and Molecular Imaging noted a significant underutilization of PET MPI relative to its demonstrated advantages in the assessment of suspected or known coronary artery disease. The advantages of PET MPI over single photon emission computed tomography (SPECT) include high diagnostic accuracy, higher spatial and contrast resolution, correction for attenuation artifacts despite body habitus, low radiation exposure, and short acquisition times. In addition, the Position Statement noted the ability of cardiac PET to evaluate myocardial blood flow, which is unique in the non-invasive imaging arena. Myocardial blood flow has several attributes including substantially reducing the risk of (coronary artery disease) CAD with a normal result, determining success of vasodilator stress, providing important risk stratification and adjudicating the presence of multivessel disease. In this Position Statement, for the first time both organizations concluded that cardiac PET MPI was a preferred test for all patients recommended for pharmacologic stress imaging. The document also concluded that Cardiac PET MPI was strongly recommended for certain categories of patients. These groups include: previous inconclusive study, body habitus limiting image quality, high risk patients, previous CAD patients needing reduced radiation exposure, and in cases in which determining myocardial blood flow would be advantageous to patient care. This Statement, in addition to the surge in supportive literature, has positioned Cardiac PET as a mainstream nuclear cardiology procedure. Despite these developments, there are roughly 250 centers in the United States performing PET MPI at present which is a small fraction of the number of SPECT cameras throughout the country (estimated to be approximately 5000). The vast majority of these centers are using rubidium-82 with circa 20 centers nationwide, mostly at university teaching hospitals, are engaging in N13-ammonia programs. Both agents are ideally suited to pharmacologic stress, hence the societal recommendations for ‘‘preferred’’ status for this form of stress alone. Currently, rubidium-82 and N13-ammonia are the only two FDA approved radiopharmaceuticals for PET MPI. The novel radiopharmaceutical 18F-flurpiridaz is currently in phase 3 clinical trials. The Phase 2 and 3 Trial datawere encouraging and the final Phase 3Trial is nearing completion. Until that time, Rubidium-82 remains the most widely used PET tracer throughout the United States andEuropedue to the distinct advantage of not requiring an Reprint requests: Stephen J. Horgan, MD, PhD, Division of Cardiovascular Medicine, Morristown Medical Center, Gagnon Cardiovascular Institute, Morristown; [email protected] J Nucl Cardiol 2021;28:300–2. 1071-3581/$34.00 Copyright 2019 American Society of Nuclear Cardiology.