Results from a large representative cohort of US children shows that an incidental finding is likely to appear in one in five brain MRI scans, researchers report.

Furthermore, one in 25 children will have an incidental finding that warrants clinical referral and one in 500 will have an abnormality requiring urgent attention, according to the study published in JAMA Neurology.

The findings provide a backdrop level of incidental findings in the general paediatric population that should be helpful to clinicians and to researchers, the authors say.

Neuroradiologists from the University of California San Francisco used data from 11,679 children (52% boys) aged 9-10 years in the Adolescent Brain Cognitive Development (ABCD) cohort, that was designed to mirror the US population.