Also known as a PET Dipyridamole stress test, this is an almost painless procedure that can help in the diagnosis of coronary artery disease and aid in identifying areas of the heart in which there is low blood flow. It may also be conducted to help evaluate a patient for possible coronary artery bypass surgery. In this test, a radioactive tracer material is injected into the patient’s bloodstream. In turn, energy rays from the tracer material show up on a PET scan, which creates 3-D images of the heart from different angles and in various slices. As opposed to a treadmill stress test, a nuclear chemical stress test uses medicine (dipyridamole) to increase the blood flow in the heart. The entire procedure can take up to three hours, and patients are able to return to normal activities immediately. You will be instructed to drink a sufficient amount of water following the test in order to help the radioactive material (which is not dangerous) to leave your body.