Whole body MRI or a targeted scan, and how to choose

The difference between the two scans

A targeted MRI looks at one part of the body, such as the brain, a knee or the lower spine, with sequences chosen for the question your doctor is asking. Our MRI uses a 3 Tesla scanner, takes 30 to 60 minutes, and uses contrast only where it is clinically indicated [1].

A whole body MRI surveys the body from the brain to the pelvis in about 60 minutes, looking broadly for signs of disease in a person who feels well [1]. Because it covers so much, it gives each area less time than a scan planned for that area alone, so it is a starting point for some questions and not the last word on any one of them.

When a targeted scan is the right choice

A targeted scan is right when there is a symptom or a finding to explain, and the result is likely to change what happens next. NICE makes this point for low back pain, advising against routine imaging outside a specialist setting and suggesting it only when the result is likely to change management [2].

Sometimes the targeted test is itself a whole body scan. For a person with a blood result suggesting myeloma, NICE suggests whole body MRI as the first imaging test, because the question concerns bone marrow throughout the skeleton [3]. The scan is chosen by the question, whatever its name.

When a whole body scan may suit you

A whole body MRI suits a well adult who wants a detailed baseline and the reassurance of having looked, and who has a doctor to decide calmly which findings matter. It adds to the screening recommended for your age and does not replace it.

The American College of Radiology does not recommend total body screening for people without symptoms, risk factors or a family history, and notes there is no evidence yet that it helps people live longer [4]. Many people still value the baseline, and our guide to full body MRI in London sets out what it finds and misses in detail.

Why a doctor should see you first

Scans show a great deal that does not explain how you feel. In a review of people with no back pain, a bulging disc was seen in 30% of 20 year olds and 84% of 80 year olds [5]. Without an examination, a finding like this can be blamed for a pain it did not cause.

A doctor who has heard your history and examined you can plan the scan around your question, including whether contrast is needed, and then read the report against what you described. That turns a picture into an answer.

Who it is not for, and the risks

MRI uses no radiation, though the magnetic field can affect some implants and devices, so the radiographer needs the make and model of anything in your body beforehand, and most orthopaedic implants pose no risk [6]. Tell the clinic if you could be pregnant, and if enclosed spaces make you anxious, because our scanners are wide bore for comfort [1].

If contrast is needed, the risk of an allergic reaction is small and reactions are usually mild. A rare skin and tissue condition is linked to contrast in people with serious kidney disease, so kidney function is checked first, and very small amounts of contrast can remain in the body after several scans, with no known health effects [6].

Some symptoms need urgent care before any planned scan. Sudden weakness or numbness, a severe sudden headache, new chest pain, or back pain with numbness around the buttocks or new loss of bladder control are reasons to call 999 in the UK or the local emergency number.

Questions that help you decide

The right scan follows from the question. These questions help you and your doctor agree on it before anything is requested.

• Is there a symptom or a finding we are trying to explain?
• Would the result change what we do next?
• Which area and which sequences answer the question best?
• Is contrast needed, and are my kidneys fine for it?
• If this is a screening scan, how will incidental findings be handled?

How The Wellness can help

If you have a symptom, a GP appointment gives you a GMC registered doctor who takes your history, examines you and requests the right scan when one is needed. A targeted MRI is from £795, reported by a consultant radiologist, and the doctor goes through the report with you [1].

If you want a baseline while well, our full body MRI is from £2,500, with a physician consultation to discuss every finding included [1]. Scans are carried out through registered partner clinics, and our own clinics are on Baker Street in Marylebone and Eccleston Street in Belgravia, open from 7am to 9pm every day.