What is a myocardial perfusion scan?

A myocardial perfusion scan (also called myocardial perfusion imaging, MPI, thallium scan, MIBI scan, technetium scan or nuclear medicine scan) looks at the blood supply to your heart muscle.

It uses a small amount of radioactive liquid (known as a tracer) so that the inside of your body can be seen more clearly, and a special camera to create pictures of how well blood is reaching different parts of your heart.

What does the myocardial perfusion scan involve?

The test usually has two parts:

• a stress scan to look at how well your heart works during activity
• a rest scan.

Stress is created in different ways: by walking on a treadmill, through your pacemaker if you have one, or by taking a medicine that makes your heart work harder. You’ll then be given the radioactive tracer through a cannula. The tracer gets absorbed by your heart muscle which allows doctors to see images of your heart more clearly. After a short break, you’ll have the scan.

For the second part of the test, you’ll be injected again with radioactive tracer and then have another scan. You may need to come back on another day for the rest scan.

Who is it for?

A myocardial perfusion scan is used if your doctors need more information about how well your heart is working, especially if you have symptoms such as chest pain and breathlessness, or you’ve already been diagnosed with heart disease.

People with chronic kidney disease (CKD) have a higher risk of heart problems, such as heart attack and stroke, so kidney patients are often offered this scan to check the heart more closely.

If you are being assessed for a kidney transplant, you might have a stress test such as a myocardial perfusion scan as part of your transplant work-up.

Is it safe? Are there any alternatives?

Myocardial perfusion scans are considered a very safe routine investigation.

You’ll be exposed to a small dose of radiation, roughly the same amount as a few years of natural background radiation that we’re all exposed to in everyday life. Your doctor will only request this scan if the expected benefits outweigh this risk.

The stress medicine may cause a few short-lived side effects such as chest tightness, headache, flushing, feeling sick or shortness of breath. But these should settle quickly, and you’ll be closely monitored.

Tell the team if you’re pregnant, think you may be pregnant or are breastfeeding, as radioactive tracers can affect a developing baby and may pass into breast milk.

Depending on your situation and the reason you’re having this test, alternatives may include include an electrocardiogram. Your doctor will choose the most appropriate test.

Where will the myocardial perfusion scan take place?

The scan is usually done in the nuclear medicine or X-ray/radiology department of the hospital, using a special camera in a dedicated scanning room.

Specially trained nuclear medicine technologists or radiographers usually carry out the scan.

Nurses or healthcare assistants may also be present to monitor you and help keep you comfortable.

What happens before the scan? 

You’ll receive written instructions with your appointment. Typically, you may be asked to:

• avoid chocolate and caffeine for 24 hours before the stress part of the test. This includes tea, coffee, some fizzy drinks and many energy drinks, as well as some cold and flu medications. This is because chocolate and caffeine can interfere with the medications used in the test
• fast for 4-6 hours before the scan (water is usually allowed)
• give the hospital team a full list of your medicines. You may be asked to pause certain heart medicines for a short time
• wear loose, comfortable clothing with a separate top and bottom, as the team will need access to your chest. Wear flat shoes or trainers is possible

If you are on dialysis the team may need to plan the timing of the scan around your dialysis session, so they will ask you to let them know your schedule.

What happens during the myocardial perfusion scan?

• You’ll meet the team before the test and you’ll have the chance to ask any questions you have.
• You’ll have a small tube called a cannula inserted into a vein in your arm for the tracer and any stress medicine.
• You’ll be attached to an ECG (electrocardiogram) monitor that records the electrical activity of your heart and have your blood pressure checked.
• The stress part of the test may involve receiving a medicine through the cannula to make your heart work faster, or you may be asked to walk on a treadmill or use an exercise bike. The team will monitor your heart and will then give you the radioactive tracer through the cannula.
• You’ll wait a short time before sitting or lying back while images are taken with the special camera, which will be positioned around your left side. This usually takes 15-20 minutes and shouldn’t be painful, although you’ll need to keep still and may be asked to raise your arm.

The rest scan will usually be carried out on a different day. You will have another cannula inserted into a vein in your arm but this time you will only have the radioactive tracer and not any medications to make your heart work harder. You will then have the images taken as before.

What happens immediately after the scan?

After the scan you can usually go home the same day.

You will be slightly radioactive for the rest of the day, so you may be advised to limit close, prolonged contact with small children and pregnant women for about 24 hours.

You’ll usually be encouraged to drink extra fluids to help flush the tracer out through your kidneys.

What should I expect when I get home?

You might feel a little tired for a day or so, and you may have a small bruise where the cannula was placed is also common.

How will I get the results?

The images are reviewed and reported by a nuclear medicine doctor or radiologist and sent to your kidney doctor. You’ll usually get the results at your next appointment.

Is there anything else I need to know?

You may not be able to bring young children into the scanning room because of the small amount of radiation used.

Let your hospital team know if you struggle to lie flat, raise an arm or do any exercise. They can plan any extra support that may be needed.

Publication date: 02/2026

Review date: 02/2029