Whole-Body MRI Screening: Radiology’s Evolving Role

Whole-body MRI (WB-MRI) screening has gained visibility in recent years as for-profit enterprises market preventive imaging to healthy, asymptomatic individuals. Although research has not demonstrated a mortality benefit, consumers are increasingly seeking peace of mind—or, alternatively, detection of disease before symptoms arise—at imaging centers and a growing number of dedicated WB-MRI screening clinics. Paying out of pocket for WB-MRIs reflects a broader trend toward greater consumer involvement in health decisions.

While they have the potential to catch diseases that may otherwise go undetected, WB-MRI exams often identify lesions that ultimately are deemed benign. A 2020 review of 12 studies covering 6214 WB-MRI screenings found that, of 17,961 abnormal findings reported, 91% were deemed benign, while 9% were considered to be oncologically relevant and requiring further investigation. Only 0.5% of lesions were found to be suspicious for cancer.¹

WB-MRI is commonly used for surveillance in patients with certain inherited cancer-predisposition syndromes like Li-Fraumeni and for management of genetic conditions such as neurofibromatosis and tuberous sclerosis complex. However, WB-MRI screening is not routinely recommended for average-risk individuals, and most insurance plans do not pay for it.

The American College of Radiology states, “there is no documented evidence that total body screening is cost-efficient or effective in prolonging life” in asymptomatic patients.²

“The way you confirm whether a screening test creates health value—that it improves the quality or quantity of your life—is with a randomized trial,” agrees Matthew Davenport, MD, Professor of Radiology and Urology, Vice Chair, and Service Chief of Radiology, and Associate Chief of Staff of the Academic Medical Center at the University of Michigan. No such studies, however, have been done for WB-MRI, Dr Davenport notes.

Established screening recommendations for cancers of the colon, breast, prostate, and cervix are supported by evidence of clinical benefit. Brian Dontchos, MD, Associate Professor of Radiology, University of Washington (UW) School of Medicine, and Physician, Fred Hutchinson Cancer Center in Seattle, says screening recommendations must demonstrate a disease-specific survival benefit, and be broadly applicable to a large population, reasonably cost-effective, and minimally invasive.

“Whole-body MRI does not fulfill these [criteria],” Dr Dontchos says. “We need a lot more time to study this before we can make the important conclusion [about a disease-specific outcome].”

“The consequences of implementing widespread screening without evidence of improved patient outcomes are illustrated by the trend of thyroid cancer screening in South Korea, where diagnoses increased 15-fold over 18 years while mortality remained stable, largely because of overdiagnosis associated with widespread ultrasound screening.”³

“Thyroid ultrasound screening generated surgeries, cost, and anxiety from findings that patients likely would have died with rather than died from,” Dr Dontchos says.

Dr Davenport adds that routine ovarian cancer screening—not recommended for asymptomatic, average-risk women—offers a similar lesson. Although a randomized trial of over 200,000 women found more early-stage diagnoses and fewer advanced-stage cases with US screening, mortality from ovarian or tubal cancer was identical in the screened and non-screened groups after a median follow-up of 16.3 years.⁴

“The authors highlighted the importance of focusing on cancer mortality as the primary outcome in screening trials, because detection alone does not necessarily translate into improved health,” he says.

Routine WB-MRI does have advocates. Sean Raj, MD, MBA, Chief Medical Officer and Chief Innovation Officer at SimonMed, believes the benefits of earlier detection outweigh the potential harms of false positives in WB-MRI. Dr Raj notes that his clinics regularly demonstrate unsuspected abnormalities, including cancers and aneurysms, in “otherwise perfectly healthy people.”

“The bottom line is that we can now see clinically significant, previously unsuspected disease before there are even symptoms,” he says.

“I’m encouraged about what whole-body MRI could potentially tell us about health before symptoms appear,” agrees Zahi A. Fayad, PhD, Director of the Biomedical Engineering and Imaging Institute and Professor of Diagnostic, Molecular, and Interventional Radiology at the Icahn School of Medicine at Mount Sinai in New York City.

The value of WB-MRI may be realized by its role in possibly preventing the need for aggressive treatments following early detection. Dr Fayad says that to establish clinical value, prospective studies comparing WB-MRI plus usual preventive care with usual care alone are needed to assess impact on disease development, quality of life, benefits, harms, and costs.

“In the meantime, commercial programs should be clear about what the scans can miss, the uncertainty surrounding benefits, and the possibility of unnecessary follow-up. [WB-MRI] should complement recommended screening, and a normal scan should never be a reason to dismiss symptoms,” he says.

While additional testing and treatment may lead to patient burdens and demands on healthcare resources, the significance of WB-MRI findings depends on clinical context and the outcome of follow-up care.

Manjiri Dighe, MD, UW Professor of Radiology, Medical Director of Ultrasound, and Vice Chair of Quality and Safety at UW Medical Center, explains that WB-MRI screens often start a “cascade” of medical tests that contribute to long wait times, high costs, and patient stress. With “some thyroid nodules” found in 50% of the population, according to Dr Dighe, MRI leads to US and then frequently to a biopsy.

“Less than 5% of any nodules seen turn out to be cancer,” she explains, adding that liver lesions create a similar testing demand, with benign cysts or hemangiomas as typical outcomes.

“We’re using these imaging slots that [patients] don’t really need … and [that] would never have been investigated further and in most cases not be a significant finding that needs treatment,” Dr Dighe says. “Current oncology patients may not get appointments in time because we’re trying to solve questions related to something seen incidentally on full-body MRI.”

Dr Davenport says incidental findings on WB-MRI are common. “Advanced imaging of a single part of the body like the abdomen detects findings of uncertain significance in approximately 20-40% of average-risk people,” he says. “When images are taken of the entire body, that rate is higher.”

Follow-up testing is not unique to WB-MRI. Many well-established screening programs consider additional testing inevitable. Nina Vincoff, MD, Chair of the ACR Patient and Family Centered Care Commission, Executive Medical Director of Prisma Health Radiology Care Division, and Editor-in-Chief of Applied Radiology, notes that about 10% of screening mammograms result in a callback, while approximately 5 cancers are detected per 1000 women screened.⁵

“We accept the tradeoff because of the potential value of detecting disease earlier,” she says.

Dr Raj explains that SimonMed utilizes advanced 3T magnets with detailed resolution and employs fellowship-trained radiologists supported by AI to characterize findings accurately. This, he says, greatly reduces the number of “indeterminate findings.” His providers also consult with WB-MRI patients on recommendations through their full-service imaging clinics. “We really hold their hand through the process.”

Not all WB-MRI providers uphold high standards for protocols, reporting, and management. Unlike targeted diagnostic exams that can draw on frameworks like BI-RADS, LI-RADS, and TI-RADS, WB-MRI screening presents challenges in maintaining consistency across organ systems. This presents an opportunity for radiology to guide responsible use, developing standardized protocols, reporting frameworks, outcomes research, and evidence-based pathways for follow-up care, says Dr Dighe.

Protocols must also be evaluated in the context of their intended use. WB-MRI protocols, for example, usually differ from those of dedicated breast MRI, which calls for tailored acquisition techniques like prone positioning and contrast-enhanced sequences to address specific diagnostic questions. A challenge with WB-MRI protocol design remains balancing exam scope and duration with the clarity required to detect abnormalities.

“There are limitations on whether the magnet can get images from head to toe within a reasonable amount of time. There’s a balance to strike between the resolution you’re trying to achieve to see lesions and the amount of time you spend in getting those images,” Dr Dighe says.

Routine WB-MRI screening is part of a larger trend toward consumer-directed, fee-for-service health testing. Demand for diagnostic medical information outside traditional clinical pathways is growing amid uncertainties around its clinical utility, appropriate use, and downstream effects. According to Dr Raj, radiologists can support the growing practice by setting clear expectations with patients prior to the screening about what the exams could show, and afterwards by contextualizing findings, ensuring that the scans do not “cause more panic than good.”

“In preventive imaging, knowing when not to do more [is vital],” he says. “If we identify a benign finding, we need the confidence to [say] it doesn’t need additional testing. When we identify one that’s potentially serious, we need a clear pathway to act. That’s how we turn more information into better medicine, rather than simply more healthcare.”

With appropriate oversight from radiology, consumer-driven imaging may yield more meaningful results.

“Radiology departments have an opportunity to lead the work of building evidence and guiding responsible use. We should help define protocols, how findings are reported, and when further investigation is warranted,” concludes Dr Fayad, adding that the examinations could contribute to research that follows people over time and establishes which measurements actually help guide care.