UMEM Educational Pearls

Category: Neurology

Title: Incidental MRI Findings

Posted: 11/3/2007 by Michael Bond, MD (Updated: 7/10/2020)
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What should I do about this finding on the MRI I ordered

Now tha ta lot of EDs are getting MRIs on a more urgent basis, we will need to know what to do with the resutls.  However, the natural history of findings on MRI has not been well studied, so what should we do with that small meningioma you find.  Well some researchers in the Netherlands have attempted to address your question. In a population-based study [Rotterdam Study] , 2000 adults aged 45 or older underwent a brain MRI.

Some of the common findngs were:

  • Asymptomatic brain infarcts were observed in 7%.
  • Aneurysms and benign tumors (mostly meningiomas) were each found in nearly 2%.
  • The two most urgent findings were a chronic subdural hematoma and a 12-mm aneurysm. Both required surgey.
  • Only two out of the 2000 (0.001%) people had symptoms related to their MRI findings (hearing loss in both).
  • The prevalence of asymptomatic brain infarcts and meningiomas increased with age, as did the volume of white-matter lesions, whereas aneurysms showed no age-related increase in prevalence.

Most of the study patients were white and middle class so these results may not be generalized to the general public.  I am sure more studies are in the works, but for now don't be two suprised if you find an asympomatic infarct or meningioma.

Vernooji MW, Ikram MA, Tanghe HL. Incidental Findings on Brain MRI in the General Population. NEJM. 2007;357(18):1821-1828.