There have been limited data available on the prevalence of structural brain abnormalities in asymptomatic individuals and a growing interest in the various ethical issues related to reporting of such findings. This study evaluated the prevalence of incidental abnormalities on brain magnetic resonance imaging (MRI) in a random sample of 60- to 64-year-old community-dwelling individuals as well as successfully followed a referral pathway taking into account of the various ethical issues related to the referral process. The Personality and Total Health (PATH) Project was designed to study the risk and protection factors of normal ageing, dementia and other neuropsychiatric disorders.

MRI scans were performed in randomly selected 478 healthy, community-dwelling 60- to 64-year-old individuals. All scans were reported for abnormalities by a radiologist.

Abnormalities were detected in 22 (4.8%) subjects, comprising 10 tumours (pituitary adenoma 4, meningioma 3, suprasellar tumour 1, cavernous haemangioma 1, subarachnoid lipoma 1), 6 infarct-like lesions, 2 arachnoid cysts, 1 possible normal pressure hydrocephalus, and 1 each of unconfirmed aneurysm and mesial temporal sclerosis. Further evaluation led to novel intervention in one case of pituitary adenoma, and adjustment of drug treatment to modify risk factors in two cases with subclinical infarction.

While no case required immediate referral or urgent surgical intervention, the change in the outcome of treatment of some cases suggests that appropriate referral process should be in place when researchers study large number of subjects in the community using MRI of the brain.