Positron Emission Tomography (PET) detects and measures glucose metabolism within the body. PET scans can diagnose certain cancers as well as any changes and spread of the cancer. It can also detect areas of living heart muscle following a heart attack.
Make sure you remember to bring any previous films or reports to the appointment. Wear warm comfortable clothing that do not have any metallic objects. You will also need to:
- Fast for six hours - fast for 6 hours prior to the test. You may drink plain water only during the fasting period
- No strenuous exercise - avoid strenuous exercise in the twelve hours before your appointment
- Take non-diabetic medication as normal - take them with plain water when you would normally take them
- Advise of pregnancy or breastfeeding - let the service know if you are pregnant or breastfeeding
If you take diabetic medication, you will need to follow additional preparations:
- Non-Insulin Dependent - if your appointment is before 12 noon, fast from midnight and do not have breakfast or your oral diabetic medication. If your appointment is after 12 noon, have your normal breakfast and oral diabetic medication, and then fast for 6 hours until your appointment
- Insulin Dependent - an appointment before 12 noon is preferred. Fast for 4 hours after your last normal meal & insulin before your appointment time. If your appointment is after 12 noon, have your normal breakfast with your insulin. Insulin should not be given less than 4 hours before FDG injection. Bring your insulin with you to the scan
Your blood sugar level and your weight will be measured. You will be asked to remove all metal objects. A small cannula needle will be placed into a vein in your hand or arm and a small amount of radioactive glucose wil lbe injected through the cannula. You will be allowed to rest quietly on the bed for one hour. You will be then asked to lie very still on a scanning table for about 30 minutes.
There are no after-effects from having a PET scan. Once it is finished, you will be given something to eat and can go home. Your results will be sent to your GP or specialist.