Cardiac Perfusion Scan: How It Is Done

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How It Is Done

A cardiac perfusion scan is usually done in a hospital radiology or nuclear medicine department, a doctor's office, or at an outpatient clinic. The test is done by a doctor and technologist trained in nuclear medicine.

Resting scan

For resting scans, in which you do not exercise, you will be asked to remove your clothing above the waist, and you will be given a hospital gown to wear. Four electrodes will be attached to your chest to keep track of your heartbeats.

For a resting scan, the injection site on your arm will be cleaned and an elastic band will be placed around your upper arm. Then a small amount of the radioactive tracer is injected, usually into a vein on the inside of your elbow.

You will lie on your back on a table with a large camera positioned above your chest. The camera records the tracer's signals as it moves through your blood. The camera does not produce any radiation, so you are not exposed to any additional radiation while the scan is being done.

You will be asked to remain very still during each scan, which takes 5 to 10 minutes. The camera will move to take more pictures at different angles. Several scans will be taken.

The entire test takes 30 to 40 minutes, after which you can resume your normal activities.

Stress scan using medicine

The stress scan is done in two parts. In many hospitals, the first images are taken while the person is at rest. Then a second set of images is taken immediately after the person is given a medicine such as adenosine, which makes the heart respond like it would to exercise. A stress test with medicine is usually used when a person cannot exercise for some reason.

For this test, you will be asked to sit or lie on the examining table and you will be given a routine electrocardiogram (EKG), which takes about 5 to 10 minutes.

Then the medicine is injected into your arm. You may get a headache and feel dizzy, flushed, and nauseated from the medicine, but these symptoms usually do not last long. Additional EKGs and blood pressure measurements are often taken. After the medicine takes effect (about 4 minutes), a small amount of radioactive tracer is injected. You will lie down on a table for a set of scans. The camera records the tracer's signals as it moves through your blood. The camera does not produce any radiation, so you are not exposed to any additional radiation while the scan is being done.

Sometimes more pictures are taken after you rest for 2 to 4 hours. You may resume your normal diet and activities after the final set of scans.

Stress scan using exercise

For stress scans using exercise, your heart rate will be checked with an electrocardiogram (EKG). Because EKG electrodes need to be attached to the chest to check the heart, men are usually bare-chested and women usually wear a bra, gown, or loose shirt. For more information, see the medical test Electrocardiogram.

The exercise stress scan is done in two parts. First a set of resting images is taken, then a set of stress images is taken immediately after exercise. In many hospitals, first resting pictures are taken using one type of tracer. More pictures are taken using a different tracer after your heart has been stressed by exercise.

In this stress test, you exercise on a treadmill or stationary bike. Your heart rate will be checked during the test with standard electrocardiography. Your blood pressure is checked using a blood pressure cuff placed on your arm. For more information, see the medical tests Exercise Electrocardiogram and Electrocardiogram.

You will begin by walking or pedaling slowly and easily. Every few minutes, the speed or incline of the treadmill or resistance of the bike may be increased. You will exercise until you need to stop or until you reach a suitable heart rate. At that point, a different tracer medicine is injected. You will probably continue to exercise for an additional 30 to 60 seconds to circulate the radioactive tracer.

You will then lie down on a table for scanning. Each scan takes 5 to 10 minutes. The camera does not produce any radiation, so you are not exposed to any additional radiation while the scan is being done.

Sometimes more pictures are taken after you rest for 30 minutes to 4 hours. You may usually resume your normal diet and activities after the final set of scans.

In some hospitals, a second injection of radioactive tracer is repeated several hours after exercise and before the final image. You may be asked to return 24 hours after the test to have another set of pictures taken.

Last updated:	December 24, 2007
Author:	Robin Parks, MS
Reviewed By:	E. Gregory Thompson, MD - Internal Medicine, Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology
Editors:	Kathleen M. Ariss, MS, Michele Cronen