Cardiac Nuclear Imaging/Myocardial perfusion imaging (MPI) is a non-invasive imaging test that shows how well blood flows through (perfuses) your heart muscle. It can show areas of the heart muscle that aren’t getting enough blood flow. This test is often called a nuclear stress test. It can also show how well the heart muscle is pumping.
MPI is useful in patients with chest discomfort to see if the discomfort comes from lack of blood flow to the heart muscle caused by narrowed or blocked heart arteries (angina). Myocardial perfusion imaging doesn’t show the heart arteries themselves, but can tell your doctor with good certainty if any heart arteries are blocked and how many. MPI can also show if you’ve previously had a heart attack.
What to ExpectJump Up
You will be positioned on an examination table. A nurse or technician will insert an intravenous (IV) line into a vein in your hand or arm. The exam will usually begin with an injection of a radioactive material called a tracer while you are resting. Within the first hour, after the tracer is injected, you will lie on a moveable imaging table with your arms over your head for about 15 to 20 minutes while images are recorded.
Following the imaging, you will undergo a stress test, which requires you to exercise either by walking on a treadmill or pedaling a stationary bicycle for a few minutes (if you would like to opt out of exercising, you will be given a drug to increase blood flow to the heart). While you exercise, the electrical activity of your heart will be monitored by electrocardiography and your blood pressure will be frequently measured.
Total time for the procedure will be approximately two to four hours. After the examination, you may be asked to wait in case additional images are needed. A cardiologist will interpret the images and compile a report.
What will I experience during and after the procedure?
Except for intravenous injections, most nuclear medicine procedures are painless and are rarely associated with significant discomfort or side effects.
Who interprets the results and how do I get them?
One of our physicians who has specialized training in nuclear medicine will interpret the images and send a report to your referring physician.
What are the benefits?
MPI tests can help your doctor:
- Find out if there are narrowings or blockages in your coronary (heart) arteries if you have chest discomfort
- If you have heart damage from a heart attack if your heart is not working normally
- Determine if you should undergo a coronary angiogram
- Decide whether you would benefit from coronary stent or bypass surgery to treat your chest discomfort or help an abnormal pumping function go back to normal
- If a heart procedure you had to improve blood flow (stent, bypass) is working
- How well your heart can handle physical activity