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PET (positron emission tomography) scanning

A PET (positron emission tomography) scan can show how a part of your body is actually working, rather than just what it looks like.

What is a PET scan? 

A PET scan is normally used alongside other tests such as an X-ray or MRI scan. Positron emission tomography (PET) uses very small amounts of radioactive glucose to produce 3D and cross-sectional images of the body. A radiologist will look at the images produced, and report the results to your doctor.

A PET scan also has a simple CT scan performed at the same time to help pinpoint any abnormal areas seen on the PET scan.

What are the benefits?

The main advantage of a PET scan over other scans such as X-Ray or MRI scans, is that it can show how a part of your body is actually working, rather than what it looks like. 

How can I prepare for this procedure?

Don’t eat anything up to six hours before your scan although you may drink water. You’ll need to drink at least one litre (two pints) of water one to two hours before your appointment. Avoid strenuous exercise and caffeine 24 hours before your scan and try to arrive in plenty of time to rest your heart.

What happens during the procedure? 

The radioactive medicine is produced on the day before your test in a machine called a cyclotron.

On the day of the scan you will have a small amount of this medicine, which is usually injected into your arm. After resting for 40 minutes you’ll then need to empty your bladder before going onto the scanner. During the scan you will be asked to lie very still on a table that slides into the middle of the PET scanner. You’ll spend two to three hours in the department, though the scan itself will last about 30 minutes.

If you are, or there is a possibility you may be, pregnant please tell the radiographer before your scan.

For more information, and if you have any queries about the procedure, speak to your consultant.

Continue taking your normal medication unless you are told otherwise.

It’s helpful if you bring any previous X-rays with you.

What’s involved in the recovery? 

You can start eating and drinking normally after your scan. It is advisable to increase your fluid intake for several hours after the scan.

When will I get the results?

Results will usually be sent to the doctor who referred you within two to three days of your PET scan. 

Paying for your procedure

The costs of a PET scan are covered by most medical insurance policies, but please check with your insurer first. If you are paying for your own treatment the cost of the procedure will be explained and confirmed in writing when you book the operation. Ask the hospital for a quote beforehand, and ensure that this includes the surgeon’s fee, the consultant radiologist’s fee and the hospital charge for your procedure.

Specialists offering PET (positron emission tomography) scanning

Dr Nazar Sharaf

Consultant Neurologist

B.Sc. MD. PhD. MRCP(Neurology)

BMI The Highfield Hospital 1 more BMI The Beaumont Hospital

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Dr Rizwan Rajak

Consultant Rheumatologist

MBBCh (Hons), MRCP, MRCP(Rheum), LLM

BMI Shirley Oaks Hospital

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Dr Salim Janmohamed

Consultant Endocrinologist & Physician

BSc, MBBS (Hons), FRCP (London)

BMI The Clementine Churchill Hospital

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Dr Nima Hashemi

Consultant Physician in Elderly Care


BMI Shirley Oaks Hospital

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Dr Michael Kotrba

Consultant Orthopaedic and Trauma Surgeon

MD, BSc Hons, FA f. Orth (D)

BMI Shirley Oaks Hospital

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