Whole-Body MRI Expands, Leaving Patients Weighing Risks

Whole-body MRI (WB-MRI) is rapidly expanding as a screening tool for healthy patients, even as radiology leaders warn that evidence of its clinical benefit remains limited and its downstream impact uncertain.

"Patients are getting whole-body MRI by the droves, so we can either let other people perform the study in a suboptimal way, or we offer it and do the best we can," said Preethi Guniganti, MD, assistant professor of radiology at Weill Cornell Medical College in New York City.

In 2023, the American College of Radiology said there is insufficient evidence to recommend total-body screening for asymptomatic patients. Still, WB-MRI is growing as a fee-for-service exam in the U.S. and globally, driven in part by for-profit companies aggressively marketing the exam as part of longevity and preventive medicine.

That growth has outpaced the evidence base, according to experts, raising questions about how commercial demand and direct-to-consumer marketing align with evidence-based screening and medicine’s obligation to avoid unnecessary downstream harm.

At the same time, several academic centers in the U.S. have also begun offering the exam to patients, either as a stand-alone service or as part of executive health programs.

Dr. Guniganti said the volume of studies currently generated by WB-MRI at Weill Cornell is minimal compared to overall imaging volume. "We're offering it because we believe we need to be on the leading edge of this technology. It’s part of a bigger vision for radiology and preventative medicine,” she said.

“At Weill Cornell, our chairman believes strongly that there is a benefit to patients being imaged at an academic institution,” Dr. Guniganti added. “We have a lot of resources to leverage that are very different from a private company.”

Those advantages include access to prior patient images, the latest technology and a system of specialists for follow-up.

Other academic institutions are approaching WB-MRI more conservatively, citing a lack of outcomes data and downstream effects.

“We offer whole-body MRI to specific patients, but we're not proponents of offering it as a screening for everyone,” said Manjiri Dighe, MD, professor of radiology at the University of Washington (UW) School of Medicine in Seattle. “We see patients coming in for follow-up imaging, and it’s the insurance companies, and ultimately the whole healthcare system, that bear those costs. These patients may also take imaging appointments from patients who desperately need an MRI for cancer treatment.”

Limited Evidence, Expanding Consequences

While countries such as Japan and Singapore have embraced WB-MRI as part of a strong screening culture, the exam is less commercialized in much of Europe and Scandinavia.

“In the Netherlands, whole-body MRI for screening healthy people is simply not allowed because there is no proof that this kind of screening is beneficial,” said Dr. Thomas Kwee, MD, PhD, a radiologist at the University of Groningen in the Netherlands.

Achieving that proof will require significant research, including a randomized, controlled clinical trial. "Unfortunately, we don't have the resources to offer 10,000 scans as part of a trial,” Dr. Guniganti said. “In the meantime, we can learn from our screening population.”

Early data from that population highlight both the reach and limitations of the screening exam. Of the approximately 160 patients scanned during Weill Cornell’s first 18 months of operation, the majority (90%) had some sort of finding, although most did not require follow-up. A smaller subset of patients (~30%) had findings that were not inherently worrisome but required follow-up, while approximately 1% of findings were malignant or suspected of malignancy.

“Simply detecting more cancers does not mean the technique is beneficial,” Dr. Kwee said. “We know from other screening programs that you can find many more cancers and still not reduce overall mortality because many of those cancers are clinically irrelevant.”

Additional concerns about screening WB-MRI include inequitable access, overdiagnosis and additional workloads for radiologists. Some studies also suggest that more than 60% of patients undergo additional imaging, most of which yield little valuable information, according to Brian Dontchos, MD, associate professor of radiology at the UW School of Medicine.

Experts have also raised concerns about equity, noting that WB-MRI, often referred to as self-pay service, may primarily be accessible to higher-income patients. This raises questions about who benefits from screening and whether those at greatest risk are being reached. This dynamic may also introduce selection bias into early data on outcomes.

“There's no follow-up on these patients, so we don't know whether these cancers would have had any impact at all on their lives,” Dr. Dontchos said. “Screening WB-MRI adds cost, anxiety, unnecessary appointments and in some cases, unnecessary biopsies and morbidity."

Follow-up procedures can include invasive interventions, which carry their own risks and may stem from findings that ultimately prove benign.

There’s also the psychological burden of the screening exam’s incidental findings. “When people know there is something in their body that should not be there, it affects their work and social life,” Dr. Kwee said. “Many people undergo further tests or even surgery, all as a result of findings that might never have caused problems.”

These downstream interventions are a central concern among critics of screening WB-MRI, who emphasize the risk of detecting clinically insignificant findings that can lead to unnecessary treatment.