What is a DATSCAN?

A Datscan looks at the function of a particular part of the brain called the basal ganglia. It will help doctors to decide how to treat patients who have a tremor.


There is no special preparation for the examination, and you may eat and drink normally before your appointment.

In regards to medication, some drugs may interfere with the scan. The doctor who referred you to us will tell you if you need to stop taking any of your medication before your scan. Otherwise take your medication as usual. Please bring with you a full list of your drugs.


If you are pregnant or breastfeeding it is essential that you let us know before your appointment date.

If you are a female of child bearing age (12-55 years old), you will be asked about your pregnancy and breastfeeding status. If you are unable to confirm you are not pregnant a pregnancy test may be performed.


All patients are entitled to have a chaperone present for any consultation, examination or procedure where they feel one is required. This chaperone may be a family member or friend. On occasions you may prefer a formal chaperone to be present (ie. trained member of staff).

The examination

Your brain examination is divided in two parts which you must attend.

After your arrival, a radiographer will explain the procedure to you and will ask you a few questions about your health records. You will then have a small amount of radioactive tracer injected into a vein in your arm. The injected tracer is carried through the bloodstream to your brain. It emits gamma rays which can be detected by a piece of equipment called a gamma camera.

Then you will be sent away and asked to return 3 HOURS after injection for the scan.

This time gap is to allow the tracer to be fully absorbed into your brain for us to see it.

During this time you may eat as normal but you should drink more than usual and empty your bladder regularly. These will help to produce better quality images.

On your return, we will ask you to empty your bladder before beginning the scan. You will then be asked lay on a scan table and the camera placed in front of your face and behind your head. The camera will move slowly around your head taking pictures at different angles. The machine is very quiet and you do not go through a tube or tunnel. In order to get reliable pictures, the camera will be very close and you will have to remain still with your head in a head holder and strap placed over your forehead. If you are unable to lay flat on your back for 45 minutes or are
claustrophobic please let us know prior to the scan.

You do not need to undress for the examination, but you may need to remove metal objects from your face, ears and/or hair as these will interfere with the quality of the pictures.

How long will it take?

The administration of the tracer takes approximately 15 minutes and the scan 45 minutes. You are free to leave the department/hospital in the gap between the first and second part of your appointment.

Who will be present?

Your scan will be performed by a Nuclear Medicine trained member of staff which stays with you in the room while scanning. In addition we might have students in our department, and they will observe the procedure if you give your permission.

Will the injection hurt?

The injection is very similar to having blood taken. It will not make you drowsy or prevent you from driving a car.

Is radioactivity dangerous?

The amount of radiation involved is similar to that from an x-ray examination. The radioactivity naturally disperses from the body and is largely gone in 24 hours. The very low risk involved is balanced against the benefit of the information the examination provides for your doctors.