A University study has voiced concern about 'check up' brain scans, which people can buy as part of a health MOT.
Researchers warn that paid-for brain scans - increasingly offered to allay fears about undiagnosed brain cancer and stroke - may do more harm than good.
They reach their conclusion having analysed the results of almost 20,000 brain scans from people who undertook the tests for a variety of reasons.
These included general health MOTs or volunteering for medical research.
None of them had any symptoms suggesting that they had an underlying brain condition.
The researchers found that almost three per cent of healthy people had an abnormality on a brain MRI scan.
But when an incidental abnormality - such as a weakened blood vessel in the brain or a benign tumour - is discovered, there is no clear next step.
There is currently no medical evidence that treatment would do more good than harm.
The experts say this lack of evidence can create anxiety as patients are left with a tough choice between risky surgery or leaving their condition untreated.
We do not have enough medical evidence to know whether we should treat the abnormalities or just leave them be. So we cannot be sure that commercial screening benefits people with incidental findings. There is also little evidence that “peace of mind” lasts for the people with normal brain scans.
The results of the study have been published in the British Medical Journal.
It is the largest review of brain scanning results ever to be conducted.
The study was funded by the UK Medical Research Council, the Chief Scientist Office of the Scottish Government, the Scottish Funding Council and the USA National Heart, Lung and Blood Institute.