A PET-CT scan is an imaging test that allows doctors to check for disease in your body and diagnose any health problems you have been experiencing.

This will then help them decide on further treatment for you. 

The scan will be carried out at our Wimpole Street site.

How does it work?

Before you have your scan, staff in the department will fully explain the procedure to you. 

The type of PET-CT scan you will have will vary depending on why you have been referred to us, but generally, you will receive an injection of a radioactive 'tracer' (radiopharmaceutical), followed by a period where you wait for your body to take up the tracer.

After a period of time, you will be scanned to determine the distribution of the tracer within your body. Depending on the distribution throughout your body, it will help our doctors to determine/rule out the cause of the problems you have been experiencing. 

Common types of PET-CT scans include:

  • Fluorodeoxyglucose (FDG) scan – some preparation will be required before the test, such as fasting, but this will all be explained to you beforehand. On the day of your scan your blood glucose level will be checked and then you will be given an injection of a tracer called FDG. You will then have a rest period of one hour followed by a scan lasting approximately 30 to 45 minutes.
  • Rubidium cardiac scan – some preparation will be required before the test, such as staying off caffeine, but this will all be explained to you beforehand. On the day of your scan, you will be given an injection while on the scanner of a tracer called rubidium to image your heart. You may also be required to have a ‘stress’ scan while on the scanner where you will have an injection of a different drug which makes your heart work a bit harder as if you were exercising.
  • Other tracers – depending on the type of scan, the imaging department will ensure you have the correct preparation and advice before your test.

As part of the test, you will require a short CT scan where you will need to keep quite still while you move through the scanner. You may be asked to hold your breath for a few seconds while the images are taken. You will be monitored the whole time you are on the bed and able to talk to the medical imaging practitioner during the scan. The scan will not be painful in any way.

For the PET-CT scan, you should expect to be in the scanner for 30 minutes to an hour depending on the type of scan you are having. 
The doctor will then look at both scans together to give a comprehensive assessment.  

How do I prepare?

The department will let you know the exact times and preparation you need to follow before your test as this will be determined by what test you are having.

Please let us know as soon as possible if you are diabetic, claustrophobic, weigh over 160kg (25 stone) or will have difficulty lying flat for up to an hour.

After the procedure

The radiation dose from this procedure is low and any additional precautions you need to follow will be advised during your preparation instructions. These will also be reiterated by the medical imaging practitioner on the day of your scan.

There are currently no related conditions associated with this test.


Telephone: 02073518186
Email:  diagnosticwimpole@rbht.nhs.uk

77 Wimpole Street