Incidental Findings in Research Imaging
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– Finding on a research imaging study that has potential health importance
– Finding discovered during the conduct of research but is beyond the aims of the research study
Wolf, et. al. J Law, Medicine & Ethics, 2008

Incidental Findings in Research Imaging
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– Overall prevalence rates of 13% to 84% *
• 9 publications , 1997 to 2006
• Range of study populations, scan protocols, IF definitions
• IF prevalence classified by need for clinical referral
– No referral needed, 13% to 40.4%
– Routine referral, 1.8% to 43%
– Urgent referral, 0.4% to 14%
– Immediate referral, 0% to 1.2%
– IF prevalence rate of 43% (2010) **
• Clinical referral /additional tests, 2.2% (5/231) (NNI=46)
• Clear medical benefit, 0.9% (2/231) (NNI=116)
*Wolf, et. al. J Law, Medicine & Ethics, 2008
**Lo, Arch Int Med, 2010; Orme, et.al. Arch Int Med, 2010

Incidental Findings in Research Imaging
– Level 1 – NO CLINICALLY SIGNIFICANT ABNORMALITY
• Examples: Minimal paranasal sinus or mastoid inflammatory disease, chronic sinusitis, venous angioma (DVA), thornwaldt cyst, choroid plexus cyst, pineal cyst, small arachnoid cyst, mega cisterna magna, non-dilated ventricular asymmetry, empty sella.
– Level 2 – MINOR FINDINGS (uncertain clinical significance, discuss with personal physician)
• Examples: Acute sinusitis (with air/fluid levels) or mastoiditis, non-specific patchy white matter lesions (probably chronic ischemia in periventricular white matter, basal ganglia or pons), chronic infarct, chronic trauma, tonsillar ectopia, severe generalized atrophy , focal atrophy (e.g. isolated brain stem and/or cerebellum), small meningioma (<3cm) without edema or cranial nerve or brain stem involvement, possible demyelinating disease (non-enhancing).

Incidental Findings in Research Imaging
– Level 3 – ABNORMAL FINDINGS (needs clinical evaluation within 1 week)
• Examples: Aneurysm, other vascular malformation (e.g. cavernous or AVM), brain mass or infiltrating lesion with minimal edema or mass effect (e.g. glioma, small possible metastases), possible acute demyelinating or inflammatory
(e.g. Lyme) disease with enhancement.
– Level 4 – ACUTE ABNORMALITY (needs emergency clinical evaluation today)
• Examples: Acute infarct (DWI positive), acute hemorrhage
(e.g. SAH, SDH, hematoma), mass with prominent edema or brain compression (intra- or extra-axial), acute hydrocephalus
(trans-ependymal CSF).

Incidental Findings in Research Imaging
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– An IF may provide early detection of an unsuspected treatable lesion.
– Research subjects implicitly entrust aspects of their welfare to the researcher and expect to be informed of IF’s with health implications.
– Out of respect for persons, the subject is entitled to information relevant to their well-being.
– The researcher is obligated to reciprocate the subject’s willingness to give of themselves in the interest of the research.

Incidental Findings in Research Imaging
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– Clear medical benefit of an IF rarely occurs.
– Sharing of IF’s may do more harm than good.
– False positive IF’s may cause anxiety, expense and added risk with no clear benefit.
– False negative IF’s may lead to a false assumption of normal health.
– The discovery, tracking and reporting of IF’s divert resources away from the science.
– A researcher’s objective of acquiring scientific knowledge differs from that of a clinical physician.

Incidental Findings in Research Imaging
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– Can IF’s be anticipated for a specific study?
– Will the images be valid for clinical interpretation?
– Who will identify & interpret IF’s?
– Is additional expertise needed?
– How will the significance of an IF be determined?
– Is the information potentially beneficial or harmful to the research subject?
– What should the subject be told and how can they be told to optimize benefit and minimize risk?
– What is described in the consent form?