Rest Imaging Study: • Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) as a bolus through a catheter inserted into a large peripheral vein. • Start imaging 3 minutes after the injection and acquire images for a total of 10-20 minutes. Stress Imaging Study: • If a rest imaging study is performed, begin the stress imaging study 40 minutes or more after the first Ammonia N13 injection to allow sufficient isotope decay. • Administer a pharmacologic stress-inducing drug in accordance with its labeling. • Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) of Ammonia N 13 Injection as a bolus at 8 minutes after the administration of the pharmacologic stress-inducing drug. • Start imaging 3 minutes after the Ammonia N 13 Injection and acquire images for a total of 10-20 minutes.