MPI scan

An MPI (myocardial perfusion imaging) scan is used to look at how well your heart muscle is receiving blood.

An MPI scan is done in the nuclear medicine department, using a gamma camera.

Preparing for an MPI scan

This scan is done over 2 separate days, usually a few days apart. You should be prepared to be at the hospital for 2 to 3 hours each day.

If you are breastfeeding, contact the department before your appointment so we can give you some extra information before you come for your scan.

There are a few things you need to do before this test. Please follow these instructions carefully, or we might have to cancel the scan.

Things to bring with you

  • A list of all your current medicines, including any you buy from a pharmacy or shop, and any herbal or homeopathic remedies
  • Something to eat (we recommend something fatty, like a cheese sandwich)

For your stress test

Do not have any caffeinated drinks, or food containing caffeine, for 24 hours before your test. This includes:

  • tea, decaffeinated tea or herbal tea
  • coffee or decaffeinated coffee
  • fizzy drinks
  • chocolate
  • cold or flu medicines containing caffeine

Please contact us for more information.

For your rest test

There are no special preparations for this test, but please bring something to eat.

During an MPI scan

You will have 2 separate appointments for this scan. At both appointments you will meet our team of technologists or radiographers, and they will explain the procedure to you. You can ask any questions about the scan.

First appointment – Stress (exercise) test

We will check that you have followed all the preparation instructions. We will check your list of current medicines to make sure they will not interfere with the test.

We will place a small plastic tube (cannula) in a vein in your arm so that we can give you injections during the test. A drip will be connected to the cannula in your arm, and the medicine in the drip is given to you over 5 minutes.

We will also check your blood pressure and place ECG stickers on your chest to monitor your heart.

The medicine will make your heart work faster, and helps to stimulate it to act as it would during exercise or in stressful situations. You might get some side effects (such as feeling flushed, lightheaded, or feeling slightly sick). These are different for everyone but, even if you do get some side effects, they should wear off soon after the drip is stopped.

Half-way through giving the medicine, we will inject you with a tracer. This is a radioactive fluid that gets absorbed by your heart muscle, and helps us to see your scans clearly.

When the medicine drip is finished, any side effects will disappear after a few minutes, and we will check your blood pressure and ECG.

You will then have a break of 45 to 60 minutes before the scan. We will ask you to eat and drink something during this time, to allow us to get a clear image of your heart.

Just before the scan, we will ask you to pee (empty your bladder), and then we will take you to the camera room. You will be asked to remove any metal items, such as a mobile phone, or wallet, from your chest area.

We will take a 3D scan (SPECT/CT) of your heart, which can take up to 20 minutes.

For this scan, you’ll be lying on your back on the camera bed with your arms above your head. You will need to keep as still as possible. Your ECG will be monitored throughout the scan.

Second appointment – Rest test

For this part of the test, you will be injected with a radioactive tracer which gets absorbed by your heart muscle. It takes time for the tracer to be absorbed, so you will need to wait 45 to 60 minutes before your scan.

We will ask you to eat and drink while you wait. The scan will be exactly the same as the one you had in your stress test appointment.

Pregnancy and breastfeeding

As the scan involves an injection of a radioactive tracer, you must tell us if you are, or think that you might be, pregnant, or if you are breastfeeding. If possible, please tell us as soon as you receive your appointment.

For all nuclear medicine scans we check your pregnancy status with you before using any radioactive tracer.

Pain during an MPI scan

Inserting the cannula might be painful for a moment, but this soon disappears.

After an MPI scan

There are no side effects after this scan and you can carry on with your normal activities.

After the scan you will still have some radioactivity left in your body. For the rest of the day, avoid any non-essential prolonged, close contact with children, and anyone who might be pregnant. This is to reduce the amount of unnecessary radiation to babies and children.

Risks of an MPI scan

We feel that the potential benefits of the scan outweigh the very small risks. We make sure the amount of radiation you receive is as small as possible.

You can read government information about radiation exposure from medical imaging.

You might get side effects during the first appointment. These are caused by the medicine that makes your heart beat faster, not by the radioactive injection.

It is perfectly safe for you to travel abroad after your scan, but many airports and sea ports are now equipped with very sensitive radiation detectors. It is possible that the very small amount of radioactivity left in your body could set off a detector as you pass through security. If you plan to travel abroad in the week after your scan, it could be helpful to take your appointment letter with you.

Follow-up appointments

If you already have an appointment booked in clinic to discuss the results of the test, please let our team know.

Your images will be reviewed by our doctors and a report will be sent to the doctor that referred you. You will get your results from them.

Resource number: 5368/VER1
Last reviewed: July 2023
Next review due: July 2026

Trusted Information Creator. Patient Information Forum

Contact us

If you have any questions about your test in the nuclear medicine department, please contact us

Phone 020 7188 4112, Monday to Friday, 9am to 5pm

Email [email protected]

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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