REDWOOD CITY, Calif., July 21 (San Francisco News Online) — A preventive full-body MRI that reportedly found a brain tumor in a former “Bachelor” contestant has put elective whole-body scans back in the spotlight, including in San Francisco, where UCSF radiology researcher Dr. Rebecca Smith-Bindman has been one of the field’s most outspoken skeptics. But for most healthy adults, the bigger question is not whether a scan can find something — it is whether it improves health enough to justify the risks, cost and follow-up testing.
What is a full-body MRI?
A full-body MRI uses magnetic fields and radio waves to create images of large parts of the body. The American Cancer Society says MRI does not expose a person to ionizing radiation, unlike CT scans.
That is one reason the scans are marketed as a lower-risk way to look for problems early. Companies have promoted them as a way to spot cancer, heart disease and other abnormalities before symptoms appear. Prenuvo, a company offering the service, has said its scans can detect more than 500 conditions, according to CBS San Francisco.
Why are doctors cautious?
Federal and specialty groups do not recommend routine whole-body MRI screening for people who have no symptoms and no specific risk factors. The Food and Drug Administration says it knows of no scientific evidence showing that whole-body scanning of people without symptoms provides more benefit than harm. The American College of Radiology says there is not enough evidence to recommend total-body screening for patients with no clinical symptoms, risk factors or family history suggesting disease.
In other words, the scan may produce pictures, but major medical organizations say that is not the same as proving the scan helps people live longer or stay healthier.
That concern is also central to the debate in San Francisco. Dr. Smith-Bindman told CBS San Francisco that there is “not a stitch of evidence” that the scan helps people live longer or better. She also warned that there could be “tremendous numbers of false positives,” leading to more testing and more worry.
What can go wrong?
The biggest downside is often not the MRI itself, but what happens after it.
The American Cancer Society says full-body scans can turn up incidental findings — often called incidentalomas — that may be harmless normal variation. The ACS says these scans can lead to anxiety, unnecessary follow-up tests and procedures, and false reassurance if a scan misses a problem that is actually there.
Matthew Davenport, a University of Michigan radiology professor, said in an ABC News report on a JAMA editorial that harms can come from “invasive testing or surgeries or follow-up of findings that are of uncertain benefit.” The editorial, coauthored by Davenport and Dr. Scott Reeder, said no major medical group recommends whole-body MRI for the general population because the benefit has not been proven.
The American Cancer Society says insurance companies rarely pay for full-body MRIs because they are not part of standard medical care. That means the decision can involve a large out-of-pocket bill as well as a medical question.
Does the tumor story change the answer?
Not by itself, experts say. A single case can show that a scan found a real problem, but it does not prove that routine screening helps most people.
The FDA, the American College of Radiology and other medical groups draw a line between targeted imaging ordered for a specific symptom or risk and whole-body screening for people who feel well. For healthy adults without symptoms, the question remains whether early detection is more likely to help than to lead to unnecessary workups.
That is why the issue is still unsettled even as the marketing gets louder. A scan can find something. The open question, according to the FDA and leading radiology groups, is whether that something is more likely to help than harm.
