Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2009 Aug 17:339:b3016.
doi: 10.1136/bmj.b3016.

Incidental findings on brain magnetic resonance imaging: systematic review and meta-analysis

Zoe Morris  1 , William N Whiteley, W T Longstreth Jr, Frank Weber, Yi-Chung Lee, Yoshito Tsushima, Hannah Alphs, Susanne C Ladd, Charles Warlow, Joanna M Wardlaw, Rustam Al-Shahi Salman
Affiliations
Meta-Analysis

Incidental findings on brain magnetic resonance imaging: systematic review and meta-analysis

Zoe Morris et al. BMJ. .

Abstract

Objective: To quantify the prevalence of incidental findings on magnetic resonance imaging (MRI) of the brain.

Design: Systematic review and meta-analysis of observational studies.

Data sources: Ovid Medline (1950 to May 2008), Embase (1980 to May 2008), and bibliographies of relevant articles. Review methods Two reviewers sought and assessed studies of people without neurological symptoms who underwent MRI of the brain with or without intravenous contrast for research purposes or for occupational, clinical, or commercial screening.

Main outcome measures: Overall disease specific and age specific prevalence of incidental brain findings, calculated by meta-analysis of pooled proportions using DerSimonian-Laird weights in a random effects model.

Results: In 16 studies, 135 of 19 559 people had neoplastic incidental brain findings (prevalence 0.70%, 95% confidence interval 0.47% to 0.98%), and prevalence increased with age (chi(2) for linear trend, P=0.003). In 15 studies, 375 of 15 559 people had non-neoplastic incidental brain findings (prevalence 2.0%, 1.1% to 3.1%, excluding white matter hyperintensities, silent infarcts, and microbleeds). The number of asymptomatic people needed to scan to detect any incidental brain finding was 37. The prevalence of incidental brain findings was higher in studies using high resolution MRI sequences than in those using standard resolution sequences (4.3% v 1.7%, P<0.001). The prevalence of neoplastic incidental brain findings increased with age.

Conclusions: Incidental findings on brain MRI are common, prevalence increases with age, and detection is more likely using high resolution MRI sequences than standard resolution sequences. These findings deserve to be mentioned when obtaining informed consent for brain MRI in research and clinical practice but are not sufficient to justify screening healthy asymptomatic people.

PubMed Disclaimer

Conflict of interest statement

Competing interests: None declared.

Figures

None
Fig 1 Prevalence of some incidental findings (*excluding white matter hyperintensities, microbleeds, and silent infarcts) on brain magnetic resonance imaging
None
Fig 2 Prevalence of neoplastic incidental findings, non-neoplastic incidental findings, silent infarcts, and white matter hyperintensities, with 95% confidence intervals
See this image and copyright information in PMC

Comment in

References

    1. Peterson CL, Burton R. US health care spending: comparison with other OECD countries. 15. Congressional Research Service. CRS Report for Congress, 2007.
    1. Illes J, Kirschen MP, Edwards E, Bandettini P, Cho MK, Ford PJ, et al. Practical approaches to incidental findings in brain imaging research. Neurology 2008;70:384-90. - PMC - PubMed
    1. Al-Shahi Salman R, Whiteley WN, Warlow C. Screening using whole-body magnetic resonance imaging scanning: who wants an incidentaloma? J Med Screen 2007;14:2-4. - PubMed
    1. Wolf SM, Lawrenz FP, Nelson CA, Kahn JP, Cho MK, Clayton EW, et al. Managing incidental findings in human subjects research: analysis and recommendations. J Law Med Ethics 2008;36:219-48. - PMC - PubMed
    1. Cordonnier C, Al-Shahi Salman R, Wardlaw J. Spontaneous brain microbleeds: systematic review, subgroup analyses and standards for study design and reporting. Brain 2007;130:1988-2003. - PubMed

Publication types