In medical or research imaging, an incidental imaging finding (also called an incidentaloma) is an unanticipated finding which is not related to the original diagnostic inquiry. As with other types of incidental medical findings, they may represent a diagnostic, ethical, and philosophical dilemma because their significance is unclear. While some coincidental findings may lead to beneficial diagnoses, others may lead to overdiagnosis that results in unnecessary testing and treatment, sometimes called the "cascade effect".[1]
Incidental findings are common in imaging. For instance, around 1 in every 3 cardiac MRIs result in an incidental finding.[2] Incidence is similar for chest CT scans (~30%).[2]
As the use of medical imaging increases, the number of incidental findings also increases.[citation needed]