What is a Myocardial Perfusion Imaging Scan (Thallium Scan)?

Myocardial Perfusion Imagining (MPI) Scan is a non-invasive technique used to evaluate the extent of heart disease.  Under normal circumstances the coronary arteries supply oxygen to the heart muscles.  When these arteries become blocked or narrowed, the heart may not receive enough oxygen leading to chest pain or breathlessness.  This scan is a Nuclear Cardiology Imaging technique using the injection of small amounts of a radioactive (thallium) substance into the blood stream.  The injected thallium can be visualised as it travels through the arteries to the heart before, during, and after exercise by a special gamma camera.

How do I know if I need the test?

Our specialist Nuclear Cardiologists can advise you whether you need the test and answer any questions you may have.

How do I prepare for the test?

Do not eat or drink any products containing caffeine for 12 hours before the test. This includes coffee, tea, coca cola and chocolate. Do not eat anything for at least 4 hours before the test. If you are diabetic however you may take medication for your diabetes and you may eat normally as you would. You may drink water at any time but you must not smoke for 3 hours before the test. You should wear comfortable clothing and low-heeled shoes or trainers so that you can walk on the treadmill.

What will happen during the test?

We will normally ask you to walk on a treadmill or if you are unable to do so we will give you a medicine to simulate exercise. Your heart rhythm will be monitored with an ECG and your blood pressure will be recorded at several times. The radioactive marker will be injected through a vein approximately 1 minute before you stop exercising. You will then be asked to lie flat on an imaging table while a special camera circles slowly around your chest for about 30 minutes. You will be asked to stay in the department and not to exercise and 4 hours later the test will be repeated without any exercise. The data from your test is processed.

What will the test result tell me?

We would hope to have your report the following day and the result will tell you the presence or extent of heart disease

What happens next?

Depending on what the scan reveals our doctors may recommend treatments such as medication, or an invasive procedure.