REDWOOD CITY, Calif., July 21 (San Francisco News Online) — A recent Fox News report about an unnamed former “Bachelor” contestant whose preventive scan found a brain tumor has put full-body MRI scans back in the spotlight. For San Francisco readers weighing whether these scans are worth the cost and the worry, the bigger question is not whether they can find anything — it is whether scanning healthy people leads to better health outcomes than the extra testing, anxiety and expense it can trigger.
What is a full-body MRI?
A full-body MRI, also called a whole-body or total-body scan, uses magnets and radio waves to create images of the body. The American Cancer Society says MRI does not use ionizing radiation, unlike CT scans.
That is one reason the scans can sound appealing. Companies market them as a way to look for problems before symptoms start. Prenuvo, for example, says its scan can detect more than 500 conditions, including cancerous tumors at an early stage.
Why are doctors cautious?
Major medical groups have not endorsed routine full-body MRI screening for people who do not have symptoms or a specific risk factor.
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 said in an April 2023 statement that there is not enough evidence to recommend total-body screening for patients with no symptoms, no risk factors and no family history suggesting disease.
The American Academy of Family Physicians recommends against full-body scans for early tumor detection in asymptomatic people. The American College of Preventive Medicine has said doctors should not use whole-body scans for early tumor detection in people without symptoms. The U.S. Preventive Services Task Force has also given pancreatic cancer screening a D rating for asymptomatic adults not known to be at high risk, meaning the harms outweigh the benefits.
In a JAMA editorial, 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.
What are the possible downsides?
The main concern is not radiation. It is what happens after the scan.
The American Cancer Society says full-body MRI can turn up “spots” or “shadows” that may be normal variations in the body. Those unexpected findings can lead to more tests, specialist visits, biopsies or procedures that turn out not to help. Doctors call these incidental findings, or incidentalomas, when they show up during a scan done for another reason.
The same problem can also work in reverse. A scan can miss disease or create false reassurance that nothing is wrong.
The American Cancer Society, Cleveland Clinic and other medical experts also warn about anxiety, overdiagnosis, overtreatment and the cost of follow-up care. The ACS says insurance companies rarely pay for full-body MRIs because they are not part of standard medical care.
Dr. Rebecca Smith-Bindman, a UCSF radiology researcher, told CBS San Francisco that there is “not a stitch of evidence” that the scans help people live longer or better, and she warned that false positives could be common. In other words, a scan can find something suspicious that is not actually dangerous.
Why does the brain tumor story matter?
Stories like the Fox News report are powerful because they show the best-case scenario: a scan that appears to catch a serious problem early. But medical experts say one dramatic case does not settle the broader question.
The issue for most healthy people is whether the chance of finding a useful answer is high enough to justify the chance of a misleading one. Matthew Davenport has said the harms can come from invasive testing, surgery or follow-up of findings of uncertain benefit.
That is why the debate around full-body MRI has become so sharp in wellness circles and in markets like San Francisco, where elective screening is easy to market to health-conscious consumers. The Bay Area connection is especially clear in UCSF’s public criticism of the scans and in CBS San Francisco’s reporting on Prenuvo’s growing popularity.
So when do full-body MRIs make sense?
The broad consensus in the sources reviewed is that full-body MRI is not recommended as routine screening for healthy people without symptoms. The more appropriate use, according to the groups cited above, is targeted imaging ordered for a specific medical question, symptom or risk profile.
That is the basic tradeoff: full-body MRI may find some serious problems early, but for most low-risk people, major medical groups say the evidence has not shown that the benefits outweigh the harms.
