REDWOOD CITY, Calif., July 21 (San Francisco News Online) — In San Francisco, where UCSF researchers have been among the strongest critics of elective whole-body screening, a recent case has renewed attention on a simple question: for a healthy person with no symptoms, does a full-body MRI do more good than harm?
A Fox News report about an unnamed former “Bachelor” contestant said a preventive scan found a brain tumor before symptoms appeared. That kind of story can make whole-body MRI sound like an easy way to catch disease early. But major medical groups say the bigger issue is not whether these scans can ever find something important. It is whether they help enough people to justify the downsides.
What a full-body MRI is
A full-body MRI, also called a whole-body MRI, uses magnetic fields and radio waves to create detailed images of much of the body. The American Cancer Society says MRI does not use ionizing radiation, unlike CT scans.
That matters because some people worry about radiation exposure from repeated screening tests. With MRI, radiation is not the issue. The concern is what the scan shows, and what happens next.
Why doctors are cautious
The Food and Drug Administration says it knows of no scientific evidence that scanning people without symptoms gives more benefit than harm. The American College of Radiology said in an April 2023 statement that there is not enough evidence to recommend total-body screening for people who have no symptoms, no risk factors and no family history suggesting serious disease.
Other groups are also cautious. The American Academy of Family Physicians recommends against full-body scans for early tumor detection in people without symptoms. The American College of Preventive Medicine says doctors should not use whole-body scans for early tumor detection in people without symptoms of illness. And the U.S. Preventive Services Task Force has given pancreatic cancer screening in low-risk, symptom-free adults a “D” rating, meaning harms outweigh benefits.
Why a scan can create problems
Supporters of whole-body MRI point to cases like the one reported by Fox News, where a scan found a tumor before symptoms began. But a single success story does not prove that routine screening helps most people.
UCSF radiology researcher Dr. Rebecca 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,” which can send people into more imaging, more tests and more stress.
That is one of the main risks medical groups talk about: incidental findings. These are unexpected spots or shadows that may turn out to be normal or harmless, but still lead to follow-up scans, biopsies or procedures. The American Cancer Society says the risk comes from those downstream effects. Cleveland Clinic says full-body MRI can also lead to overdiagnosis, meaning a condition is found that may never have caused symptoms or death.
There is also the chance of a false negative, when a scan misses a problem. That can give a person false reassurance.
What about cost?
The American Cancer Society says insurance companies rarely pay for full-body MRI because it is not part of standard medical care. WebMD reported that scans can cost $2,000 or more and are usually not covered by insurance.
That makes the decision less about a quick checkup and more about paying out of pocket for a test that has uncertain value for healthy people.
What the recent case does and does not show
Prenuvo, a company that sells full-body MRI scans, has said the test can detect more than 500 conditions, including some cancers at an early stage, CBS San Francisco reported. But in the same report, Smith-Bindman said there is no proof the scans improve lifespan or health outcomes.
That view matches a JAMA editorial discussed by ABC News. The editorial, written by Matthew Davenport of the University of Michigan and Dr. Scott Reeder, said no major medical group recommends whole-body MRI for the general population because the benefits remain unproven. Davenport said the harms can come from invasive testing or surgery after findings whose value is uncertain.
For readers weighing an elective scan, the point is not that full-body MRI can never find something useful. It can. The question is whether, for people without symptoms or known high risk, the chance of benefit is high enough to outweigh false alarms, extra testing, worry and cost. Right now, major medical groups say the evidence does not support routine screening.
