title: Noninvasive evaluation of regional myocardial perfusion in 112 patients using a mobile scintillation camera and intravenous nitrogen-13 labeled ammonia.
abstract: The short half-life positron emitter 13N, as labeled ammonia (13NH4+), was evaluated as a myocardial imaging agent. Regional myocardial uptake of 13NH4 correlated with the distribution of labeled microspheres in experimental myocardial infarction. Using intravenous 13NH4+, myocardial scintigraphy was performed in 85 cardiac patients and 27 normal subjects. Ninety-five scintigrams were suitable for analysis. Eighteen of 24 normal subjects had homogeneous myocardial images; six had inhomogeneous images attributable to early technical problems. Perfusion defects were observed in the scintigrams of 82% (57/65) of patients with coronary artery disease, being most common in patients with myocardial infarction (27/28). Six sequential studies showed changes in perfusion consistent with the clinical course of each patient. Scintigraphic abnormalities were also observed in 4/6 patients with valvular heart disease. 13NH4+ myocardial scintigraphy is a valid and sensitive method of assessing regional myocardial perfusion and is especially useful for sequential imaging at short intervals.
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000641:Ammonia; D000787:Angina Pectoris / Q000175:diagnosis; D000818:Animals; D003326:Coronary Circulation; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006349:Heart Valve Diseases / Q000175:diagnosis; D006801:Humans; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis; D009206:Myocardium / Q000378:metabolism; D009590:Nitrogen Radioisotopes; D011877:Radionuclide Imaging / Q000295:instrumentation*; D013552:Swine; D013667:Technetium
chemical_list: D009590:Nitrogen Radioisotopes; D013667:Technetium; D000641:Ammonia