What is a Myocardial Perfusion Scan?

Nuclear Cardiology – Myocardial Perfusion

A Myocardial Perfusion Scan images the blood supply (perfusion) to the heart muscle using a gamma camera. The blood supply is made visible to the camera by the introduction of a small amount of radioactive trace (Myoview) injected into an arm vein.  Occasionally an alternative tracer called Thallium is used. Depending on the exact heart condition in question, the procedure may be performed at rest, with the heart under stress or, most commonly, both.

Myocardial scans give information useful in diagnosing and managing conditions such as coronary artery disease, dead tissue resulting from a lack of blood supply (infarcts) and diseases of the heart muscle (cardiomyopathy).

Stress Test

A Stress Myocardial Perfusion Scan examines the blood supply (perfusion) to the heart muscle using a gamma camera.  The blood supply is made visible to the camera by the introduction of a small amount of radioactive tracer,  injected into an arm vein.  The injection is given during stress exercise on a treadmill, then again while resting later on.

After each injection, a gamma camera placed over the chest takes images (maps) the pattern of tracer accumulated in the heart’s left ventricle.

What happens during a Myocardial Perfusion Scan?

This procedure requires two appointments and may take place over one or two days.

A. Before your heart scan

What to bring

• A referral from your doctor or medical specialist, and an appointment is required for this examination.
• Any relevant previous imaging
• Your Medicare cards and concession cards
• All of your current medications in their containers

Preparation – one day before your scan

A referral from your doctor or medical specialist, and an appointment is required for this examination.

Before you attend your appointment, please read and follow the printed instructions exactly.

During the 24 hours before your appointment time:

• DO NOT drink any tea, coffee, chocolate or cola drinks (even small amounts).
• DO NOT eat anything containing caffeine (even small amounts).
• DO NOT eat chocolate.

Please call Envision Medical Imaging immediately if you have any further questions or need any clarification.

Preparation – on the day of your scan

• Four hour fast before appointment  – water and medication only.
• If you are pregnant, breastfeeding, or caring for a small child on the appointment day, please notify us in advance to receive special instructions.
• WEAR loose, comfortable clothes and suitable footwear for the stress test

When you attend your appointment at Envision Medical Imaging you will be asked to answer a few safety questions. You will also be asked to remove any jewellery or watches that may interfere with the scan.

B. During your Heart Scan

Scan

A nurse will explain and prepare you for the stress test, which includes introducing an intravenous cannula (a small tube for taking blood samples and administering medicines) and electrocardiogram (ECG) monitoring during the treadmill exercise. A doctor will then speak to you before you start the exercise process. If exercise presents problems for you the doctor may suggest either trying gently exercising on the treadmill or an alternative stress method using a pharmaceutical.

For the test to give useful results it is important to stress the heart sufficiently, so the exercise will increase in intensity for as long as tolerable. Near the end of the exercise, the doctor will inject the radioactive tracer through the intravenous cannula.

After 20 to 60 minutes resting, the technologist will position you in the gamma camera and begin imaging. The gamma camera is a large square radiation detector which rotates around the chest (SPECT). There are no unusual sensations or discomfort, and the scan takes 15 minutes.

The images are usually combined with a low dose CT scan done at the same time on the same scanner. This SPECT/CT improves the accuracy of the information, and adds a few minutes to the procedure time.

Following the first scan, you may leave the department and eat/drink as normal before returning for the rest of the procedure. The technologist will inject more Myoview/tracer, and ask you to wait, resting from 30 to 60 minutes before repeating the scan to show the heart perfusion at rest.

Please allow up to five hours for the complete procedure.

Risks and side effects

Nuclear medicine examinations are considered very safe with almost no reported adverse reactions attributable to the radiopharmaceuticals used in these examinations.

Nuclear Medicine studies require very small doses of gamma radiation and are only performed where the benefits of the examination are deemed to outweigh any potential risks. At Envision Medical Imaging you can be assured that using the latest technology and with staff trained in radiation reduction techniques, radiation doses are kept as low as reasonably possible.

If you are worried or concerned about having a Stress Test you should discuss this with your referring doctor or medical specialist before coming for your examination.

If you are a diabetic on insulin treatment you should advise the nurse on arrival.

If you think you may be pregnant, please inform our Nuclear Medicine team before your examination commences.

Who will perform my examination?

At Envision Medical Imaging your stress test procedure will be carried out by a Nuclear Medicine Technologist who has a degree in Medical Radiation Science and is accredited by the ANZSNM.

What happens after a Myocardial Perfusion Scan?

How do I receive my results?

Your images will be reviewed along with your relevant medical history, and any other imaging, and be reported by our Nuclear Medicine credentialed radiologist or Nuclear Medicine physician (a medical doctor specialising in the interpretation of Nuclear Medicine studies). If your results are needed urgently, Envision Medical Imaging will arrange to have your results available immediately. Otherwise your referring doctor will receive your report within 48 hours of your examination. Please ensure that you make a follow up appointment with your referring doctor to discuss the results.

Post-procedural information

Radiation from the injected radiopharmaceutical diminishes to a very low level by the end of the procedure, and you are free to resume normal activities. If you are caring for a small child, or breastfeeding, we may ask you to take some minor precautions.

Download an Information and Consent Form

• Nuclear Medicine Information and Consent Form