What happens during a PET scan

PET scans are usually carried out on an outpatient basis. This means you won't need to stay in hospital overnight.

It's important to arrive on time for your scan, as theradiotracer used has a short shelf-life and your scan may be cancelled if you're late.

Preparation

Your appointment letter will mention anything you need to do to prepare for your scan.

You will usually be advised not to eat anything for six hours beforehand. Drinking is allowed, butyou should ideally just drinkwater. You should also avoid strenuous exercise for 24 hours before your appointment.

It's a good idea to wear loose comfortable clothes, as you may be able to wear these during the scan(although sometimes you may be asked to change into a hospital gown).

Try to avoid wearing jewellery and clothes containing metal (such as zips), as these will need to be removed.

Radiotracer injection

Before the scan,the radiotraceris injected into a vein in your arm or hand. You will need to wait quietly for about an hour, togiveit timeto be absorbed by the cells in your body.

It's important to relax, keep as still as possible, and avoid talking while you wait, as moving and speaking can affect where the radiotracer goes in your body. You can go to the toilet if you need to at any point.

The scan

For the scan, youlie on a flat bed that will bemoved into the centre of the large, circular scanner.

You should stay still and not talk while the scanner takes pictures of your body, which usually takes up to 30 minutes.

The scan is completely painless, but you may feel uncomfortable lying still for this long. If you feel unwell at any point there is a buzzer you can press to alert the medical team. The medical team will be able to see you throughout the scan.

For some people, being inside the scanner can be an unpleasant experience. Inform the hospital before the day of the scan if you think this may be a problem for you. They may be able to arrange for you to have a sedative to help you relax during the scan.

Afterwards

You should not experience any side effects after a PET scan andshouldusually be able to go home soon afterwards.

The results of your scan will not usually be available on the same day. They will be sent to your specialist to be discussed at your next appointment.