What is a PET/CT scan?
- PET stands for Positron Emission Tomography. It's an imaging technique that uses small quantities of a radioactive tracer called 18F-Fluorodeoxyglucose (similar to sugar), to produce images showing how your body is functioning
- CT (Computed Tomography) utilizes X-rays to produce images based on the density of different organs giving a structural image of your body
- By combining these two techniques in one scanner, we're able to provide images of your body that show your doctor both structural and functional information to help them plan an appropriate treatment for you
Who will I see?
- A small team of technologists and clinical assistants will look after you during your visit and one of the technologists will carry out the scan
Is it safe?
- There is a small amount of radiation involved in the procedure, similar to other diagnostic scan procedures such as CT
- The risk associated with this is very small and it's considered that the risk of missing a serious problem if you don't have a PET/CT scan is much higher
- It's safe to say that within 8 hours there will be an insignificant amount of radioactivity in your body
- And please remember that this imaging technique has been used safely since 1973, with many thousands of examinations being performed on patients around the world each day
Do I need an injection?
- Yes, in order for us to obtain images, we'll give you an injection of a tracer into a vein – usually your arm
- This feels similar to a blood test
Before the scan
- Prior to the day of your scan, if you've not already done so, please advise us if you:
- Are diabetic
- Are pregnant, breast feeding or in contact with young children
- Have any special needs
- Are claustrophobic
- Weigh over 100kg
- Are booked for other appointments on the same day
- Suffer from allergies or asthma
- Have had chemotherapy or radiotherapy
- Have a follow up appointment with your Doctor
- Have arranged your own transport
- In some circumstances, we may give you a mild sedative to enhance the results of your scan. If this is necessary, it'll be discussed with you prior to the day of your test so that you can arrange for someone to accompany you home. If you're given this mild sedative, we recommend that you don't drive for 24 hours following your scan
- It's very important that you arrive on time for your appointment as the injection you're given has a very short shelf life - this means that if you're late, we won't be able to proceed with your scan. If you're unable to attend or are going to be delayed, please contact your centre at the earliest opportunity
Can I eat or drink on the day of the scan?
- Unless we tell you otherwise, please don't have anything to eat or drink for 6 hours prior to your appointment, although you can drink plain water
- We encourage you to drink plenty of plain water both before and after your scan (approximately 4 to 5 glasses) as this helps flush the injection we give you through your body
- You may continue to use the toilet as usual prior to your scan
What happens during my appointment?
- Then you arrive you should go to the reception desk - please bring your appointment letter which may have details of who to ask for
- The technologist or another member of staff will meet you and explain the procedure to you
- You'll get the chance to ask any questions you might have and a member of our team will ask you a few questions about your clinical history
- You may be asked to change into a gown and remove any jewellery or metallic objects. Your clothes and personal items will be kept safe for you
- We'll give you an injection of a tracer into a vein, usually your arm - this feels similar to a blood test
- After receiving the injection you'll need to rest and remain lying down for approximately 1 hour while the injection is absorbed into your body
- You may be asked to remain silent during this period
- Once the tracer has been absorbed into the body, you'll be asked to visit the toilet, and you're then ready for your scan
- In the scanning room, you'll be asked to lie down on your back on the scanning bed
- The bed will move through the ring of the scanner and collect images for between 30 to 60 minutes, depending on the type of scan that you need
- The technician operating the scanner will be able to see and hear you at all times throughout the procedure
Will it be uncomfortable?
- You'll feel no pain during the scan
- It's possible that the needle for the injection may cause some slight discomfort, although this is typically no worse than for a blood test
How long will it take?
- You should allow a total of between two and a half and three hours for your scan, including the preparation time
- It can sometimes be a little longer, it all depends upon the specific diagnosis being sought as well as the particular machine we're using
After the scan
- After your scan you can eat and drink normally and are free to go home or return to work if you need to
- We recommend that you don't have close contact with pregnant women or young children for 8 hours after your scan
- We'll also encourage you to drink plenty of fluids of any type as this will help flush any excess tracer through your kidneys
Are there any side effects?
- There are no known side effects, including from the injection of the tracer
- In some circumstances, we may give you a mild sedative to enhance the results of your scan. If this is necessary, it will be discussed with you prior to the day of your test so that you can arrange for someone to accompany you home. If you're given this mild sedative, we recommend that you don't drive for 24 hours following your scan
When will I get the results?
- The radiologist will check the scan results shortly after your appointment and will send a report within a few days to your doctor or consultant
- You'll need to contact your doctor or consultant to get your results
Can I bring a relative or friend?
- Yes, but you must ensure that they're not pregnant, that there is no possibility of them being pregnant and that they're not under 18 years of age - this is for safety reasons
- Relatives or friends will only be allowed to go into the examination room in special circumstances - again, this is for their own safety