What is a false positive finding?
The term means that a test or examination gives a positive or suspicious result even though the person does not have the disease that the test is looking for.
In diagnostic imaging, a harmless cyst, scar tissue, or normal variation may resemble something that needs to be investigated. The finding is not an error in the sense that the radiologist has seen something that is not there, but the uncertainty is about what the change means.
Read also about incidentaloma at MRI when the change is discovered outside the original question.
Why do false positive results occur?
Screening needs to be sensitive so as not to miss relevant disease. High sensitivity often means that even harmless changes are detected.
The risk is affected by how common the condition is in the group being tested. When the condition is uncommon, a higher proportion of positive results will be false.
Image quality, previous examinations, radiological criteria, and the person's risk profile affect how a finding is categorized.
How should you react to a suspicious screening finding?
A screening finding is rarely an emergency diagnosis in itself. Follow the recommended schedule and ask what risk level the radiologist has indicated.
However, seek help more quickly if you also have acute or clear symptoms that have not been assessed, such as neurological deficits, severe bleeding or a rapidly deteriorating condition.
Do not interrupt ongoing medical treatment or start treatment for a suspected diagnosis before it has been confirmed.
An abnormal screening result needs to be interpreted and sometimes confirmed before disease can be determined.
What consequences can a false positive result have?
Common consequences are new images with a more targeted protocol, ultrasound, laboratory tests or check-ups after a set period of time.
Some people need a biopsy or other invasive test. Such procedures can cause discomfort, bleeding, infection, and expense even when the results are ultimately benign.
Anxiety during the waiting period is a real burden. Clear information about probability and next steps reduces the risk that an uncertain finding is perceived as a ready diagnosis.
How does healthcare reduce the risk of unnecessary follow-up?
Radiological guidelines often categorize findings by size, appearance, and risk factors. Low-risk findings may be left without action, while others are followed up or investigated.
Previous images are valuable. A change that has been stable for a long time can often be assessed differently than a new finding.
A targeted examination can provide higher detail or a different type of information. Biopsy is used when imaging diagnostics cannot provide sufficient certainty.
Questions to help you understand the results
Ask whether the finding is likely benign, uncertain or clearly suspicious and what probability the assessment is based on.
Ask for a concrete plan: no action, comparison with previous images, check after a certain time or targeted investigation.
Try to distinguish between the words findings, suspicions and diagnosis. They describe different steps and do not mean the same thing.