Have you ever had an imaging test and the results showed something abnormal or inconclusive that was unrelated to the purpose of your test? If so, you are not alone. Chances are the finding was nothing serious. However, it was probably more than a little scary at the time. This raises the question of whether there are there are medical abnormalities you're better off not knowing about.
Physicians call these observations of unexpected, potentially clinical significant results in people with no symptoms "incidental findings." They're more common than you might imagine.
In a review of 1,426 scans from the Mayo Clinic, almost 40 percent (567) showed at least one incidental finding and of these, 6.2 percent (35) required further clinical activity. Four patients had a serious disease that they may not have otherwise learned about. Incidental findings were highest in CT (computed tomography) scans of the abdomen and pelvis.
Similarly, in a review of 1,750 PET (Positron Emission Tomography) scans of patients who had known or suspicious tumors, clinicians found 58 abnormalities in 53 patients. Forty-five patients had an additional imaging test and of them, 42 had a subsequent biopsy. Physicians found malignancies or premalignant tumors unrelated to the known primary tumor in 30 percent of the biopsies cases. Most patients had no known symptoms related to the incidental finding.
The likelihood that you will have an imaging test that shows an abnormality increases as you age. Overall, one in every 7.3 asymptomatic persons scanned will have an incidental finding.
Incidental findings also pose an ethical dilemma for researchers, and there's much debate in the medical community as to whether to tell participants of these finding. Researchers and physicians fear causing worry, additional screening tests, and unnecessary medical procedures for something that may not be clinically significant. Furthermore, research scientists may not be qualified to assess incidental findings and judge whether the finding is serious and may pose a health risks.
So, how do you protect yourself from incidental findings?
First, don't worry unnecessarily. Most incidental findings are not significant. If your physician recommends an imaging test, discuss the pros and cons and decide if it really makes sense.
Remember, every medical procedure comes with some level of risk. Do not assume an unexpected finding requires further additional medical testing and seek a second opinion if you have questions.
If you participate in a research study that requires imaging studies, discuss with the researchers beforehand how you want them to handle an incidental finding.
Sources:
Helen Jaques. "Unexpected findings on medical imaging are usually harmless." Blog posting. Web. 28 September 2010.
http://www.helenjaques.co.uk/blog/2010/incidental-findings-medical-imaging/
Jeffrey Dach MD. "PSA Screening for Cancer, the Failed Medical Experiment." Blog posting.
http://www.drdach.com/PSA_Screening.html
Phend, Crystal. "Incidental Findings Common with Brain MRI." Medpage Today. Web. 31 October 2007.
http://www.medpagetoday.com/Neurology/GeneralNeurology/7164
National Institute of Biomedical Imaging and Bioengineering. "NIBIB Points to Consider for Investigators: Incidental Findings in Imaging Research. Web. 15 June 2009.
http://www.nibib.nih.gov/Research/Resources/PointsToConsider
Radiological Society of North America. "Incidental PET Findings May Reveal Undetected Cancer." Radiology. Web. 27 January 2004.
http://www.radiologyinfo.org/en/news/target.cfm?ID=185
