Radionuclide angiography in congenital heart disease.

Cardiac nuclear imaging (radionuclide angiography, electrocardiographic gated ventriculography and myocardial scintigraphy) provides structural and functional information simultaneously. This method extracts accurate quantitation of cardiovascular hemodynamics and unique information regarding myocardial perfusion. It is a reliable and relatively simple and atraumatic technique because the only discomfort to the patient is a simple intravenous injection. These studies are carried out rapidly in out- or inpatients. Radionuclide angiography is ideal also to assess the effect of exercise, oxygen or drugs on cardiac function. The radiation exposure associated with current nuclear imaging is within the range of common radiographic procedures and many times lower than that of cardiac catheterization. The use of newer radionuclides such as iridium-191m with a physical half-life of 4.96 seconds will result in a dramatic decrease in the radiation exposure to patients undergoing radionuclide angiography. Also, newer and smaller computerized gamma cameras will provide studies of improved spatial resolution and accuracy. The future of pediatric applications of cardiac nuclear imaging is bright.