Sometimes called a cardiac blood pool scan or radionuclide ventriculography, a nuclear scan uses radiation-detecting cameras to provide an image of a patient’s heart in order to determine how well blood flows to the heart muscle. A nuclear scan can give a provider information about the causes of chest pain, the extent of blockage in the coronary arteries, or the prognosis of a patient who has had a heart attack. Nuclear scans are also used to determine the level of exercise that is safe for a heart patient.

A nuclear scan is usually performed in conjunction with an exercise stress test on a treadmill or bicycle, though medications can also be given through an IV that attempt to simulate exercise. After a patient reaches his or her maximum level of exercise, a small amount of radioactive material is then injected into his or her bloodstream. The nuclear material mixes into the patient’s blood, and is carried to the heart.

The nuclear material in the patient’s bloodstream can be seen and photographed using a special device called a gamma camera. The first photographs are taken after the exercise test and show blood flow to the heart during exercise. The patient then lies quietly for 2-3 hours and another series of photographs is taken. These photographs show blood flow to the heart muscle during rest.