Myocardial Perfusion scan

		Dr Sabina Dizdarevic MD MSc FRCP Lead Consultant in Nuclear Medicine BSUH NHS Trust Department of Imaging and Nuclear Medicine Honorary Senior Clinical Lecturer Brighton & Sussex Medical School

 

The information on this page is for patients who are having a myocardial perfusion scan using thallium. It explains what it is for, what is involved and any significant risks that there may be.

       
Normal                                            Abnormal

What is a thallium scan?
It is a scan of the heart to diagnose heart disease. The scan assesses the blood flow to your heart and shows how well your coronary arteries (the blood vessels that supply the heart muscle) are working. It involves having an injection of a very small amount of radioactive material, Thallium (tracer) into a vein. The tracer gives off x-rays or gamma-rays which can be detected by a special cameras, so we can take pictures of your blood as it travels around the body.


Why are you having it?
If you have chest pain or shortness of breath this scan allows the doctor to look at the blood supply to your heart to discover the reason for your chest pain or breathlessness. It is non-invasive, in that no instruments are used inside the body.

Preparation
Eat only a light breakfast if your scan is in the morning or a light lunch for afternoon or evening scans.
Wear appropriate clothing and comfortable shoes, as you will be asked to do some gentle exercise. Trousers are best.
Bring your tablets or a list of the tablets you take. For most scans there is no need to change any medication.
Please do not bring children with you to the department. This is to aviod exposing them to unnecessary radiation.
Female patients: You should not have this scan if you are pregnant or might be pregnant

What does the scan involve?
The scan is in two parts and may be performed by a doctor, a specialist nurse or technician.
During the first part we make your heart beat faster by injecting a drug and/or by asking you to walk on a treadmill, or cycle on an exercise bike. We will then give you an injection containing a small amount of radioactive material, Thallium, into a vein in your arm. Then we take pictures of your heart straight away using a special cameras. This takes about 15 minutes and you will need to keep very still. We will then ask you to return to the department two to four hours later for the second part of the test. During this time you may drink water or fruit juice but you must not eat anything (unless you have diabetes) or do any physical activity.

The second part does not usually involve injections (however, occasionally a second thallium injection may be necessary). Further pictures will be taken lasting about 15-30 minutes.

Is there any risk from the radiation?
These scans are very safe. We use very small amounts of radioactive material to allow us to take pictures or scans; these amounts have been shown to be extremely safe in adults and children. The benefits of the scan far outweigh the risk to your health.
Please speak to your specialist doctor before your scan if you have any concerns about this risk.

Are there any side effects?
No. The radioactive tracer will not make you sleepy, nor will it prevent you from driving a car.

After your scan
You can eat and drink normally. You may go anywhere you wish; but please avoid prolonged close contact with children for the rest of the day. this is to avoid exposing them to unnecessary radiation, however small.