Incidental findings after an MRI, and what happens next

What an incidental finding is

An incidental finding is anything a scan shows that has nothing to do with the reason it was done. On a scan of a well person, almost every finding is incidental, because there was no symptom to explain.

They are common, and they become more common with age. In 2,000 adults from a Dutch population study, brain MRI showed silent old strokes in 7.2%, small aneurysms in 1.8% and benign tumours, mostly meningiomas, in 1.6% [1]. On the spine, a review of people with no back pain found worn discs in 37% of 20 year olds and 96% of 80 year olds [2]. Many of these changes are part of normal ageing.

What happens in the first days after the report

A consultant radiologist writes the report, describing each finding and often suggesting what, if anything, should follow. With our full body MRI, a physician then sits down with you to go through every line, so you never read a report alone [3].

Most findings need nothing further, and the doctor tells you so with the reason. Some are best checked with a repeat scan after an interval, to show they are stable. A few need a specialist opinion or a different test soon, and the doctor arranges that and tells you how quickly it should happen.

If the report raises a question the doctor cannot settle from the images alone, the radiologist can be asked directly, and earlier scans are often the quickest answer. A finding that has not changed in several years is usually reassuring, so it is worth tracking down any previous scans and reports, wherever they were done.

Common findings and what they usually mean

Simple cysts in the kidneys or liver, small nodules in the adrenal glands, worn discs and bulges in the spine, and small bright spots in the brain are among the most frequent findings on a body or brain MRI [1] [2]. Each has its own published rules for follow-up.

The American College of Radiology publishes algorithms for findings such as adrenal nodules, which use the size and appearance on the scan, and your age and history, to say when a finding is clearly benign and needs no further follow-up, and when it should be checked again [4]. A doctor who knows these rules can often settle a finding on the day.

When a finding needs more

Some findings do need follow-up. In a review of brain and body MRI in adults without symptoms, 20.5% of the findings judged potentially serious, where a final diagnosis was known, proved to be serious [5]. That means most worrying findings turn out well, and a minority lead to useful early care.

The next step is chosen to answer one question at a time. It may be a dedicated scan of one organ, or a consultant who sees that kind of finding every week. Before you agree to it, the doctor explains what each step could show and what it would change.

Risks and limits of follow-up

The main risk of an incidental finding is the follow-up itself. The American College of Radiology is concerned that screening scans find many non-specific results that lead to further tests and procedures without improving health, at real expense [6]. Waiting for a repeat scan can also be unsettling.

A finding that is left alone is a decision, made on evidence, and you can always ask for the reasoning in writing. A clear report has limits too, so a new symptom later deserves its own assessment. A severe sudden headache, weakness on one side, new chest pain or sudden breathlessness needs urgent care, so call 999 in the UK or the local emergency number.

What to agree before the scan

The calmest experience comes from deciding in advance how findings will be handled. Choosing Wisely UK suggests asking about benefits, risks, alternatives and doing nothing for any test, and the same questions work for each follow-up step [7].

• Who will explain the report to me, and when?
• Do I want to hear about findings of uncertain importance?
• Which findings would you leave alone, and why?
• If a repeat scan is suggested, what would change my plan?
• Can I have the images and report to keep with my records?

How The Wellness can help

If you already have a report from elsewhere, a GP appointment gives you a GMC registered doctor to read it with you, explain each finding in plain words, and agree what, if anything, should follow. Bring the report and, if you can, the images.

If you are considering a scan, our full body MRI includes a physician consultation to discuss every finding, and scans are carried out through registered partner clinics [3]. Our clinics are on Baker Street in Marylebone and Eccleston Street in Belgravia, and when a specialist is needed we arrange one and bring the letter back into your record.