Brain MRIs Can Produce Some Surprises!

Magnetic resonance imaging (MRI) of the brain is now done routinely in some conditions, such as unexplained headaches or suspected tumor. As part of the Rotterdam Study being performed in the Netherlands, 2000 volunteers underwent a brain MRI to determine the frequency of unexpected brain abnormalities that weren’t producing any symptoms. The findings were reported in the New England Journal of Medicine.

The average age of the volunteers was 63, ranging from 46 to 97. The major incidental symptomless finding was a brain infarct – dead brain tissue due to interruption of the blood supply, i.e. a stroke – in 7.2% of people. Cerebral aneurisms (bulges in a brain blood vessel, liable to burst) were seen in 1.8%, and benign brain tumors (chiefly meningiomas) were seen in 1.6% of the participants. The infarcts and meningiomas were more common in the more elderly volunteers, whereas the aneurisms showed no age-related increases.

These ‘coincidental’ findings are clearly relatively common, found in more than one in ten persons. What to do if you get a report of a chance discovery like this? It all depends on the actual finding, of course. Referral to a specialist is the first step. This should allow a decision as to whether anything needs to be done (e.g. surgery) or not. As more data are gathered on follow-up in such cases, it should become possible to have a better idea as to the relative importance of each ‘chance finding’ discovered.