Ads for elective body scans not full image

Benefits touted while risks not mentioned

Companies offering full-body computed tomography (CT) and magnetic resonance imaging (MRI) scans frequently make unsubstantiated claims about what the scans can do, but rarely give information about the limitations and risks of the tests.

Judy Illes, PhD, senior researcher at the Palo Alto, CA-based Stanford University Center for Biomedical Ethics, was the leader of a team that researched ads from companies providing medical imaging directly to consumers without physician referrals. In analyzing 40 advertisements from companies providing the scans, she says the Stanford team found the industry is lacking guidelines requiring them to present a more balanced and accurate image of the technology.

"People are capable of being very savvy consumers of medical technology, but the information has to be available to them to allow them to be savvy," Illes explains. "While we can appreciate that, in a short telegraphic ad, not all the information can be presented, but it should at least refer to other sources as well as to more thorough information on the company’s own web site or in their printed brochures."

Lacking in information

She says almost none of the ads she studied provided balanced information, cautions, or encouragement to seek medical advice before having one of the screens, which can cost more than $1,000 and are rarely, if ever, covered by insurance.

"In pharmaceutical ads, people are encouraged to ask for their doctors’ advice," Illes adds. "Why is that not the case here?"

Illes’ team analyzed ads from nine companies that ran from 2001 to 2003, as well as brochures obtained from 20 companies. The ads were rated in seven categories: references to the technology’s ability to detect diseases; emotion, empowerment and assurance; financial incentives; unsupported statements; appeals based on the popularity of the procedures; statistical information; and images.

While the study found the ads and brochures referred consumers for additional information to other sources at the company, the researchers noted, "Virtually none referred to secondary sources of information, such as a primary-care physician, or mentioned risks of having a scan." The raters also found statements that were scientifically unsupported in one-third of the advertisements and one-fifth of the brochures, Illes says.

"Direct-to-consumer marketing about new imaging procedures has the potential to enhance consumer choice," the authors wrote. "However, if the information presented to consumers overestimates the value of technologies and does not reasonably disclose risks, then choice is constrained, not enhanced."

Profiting from fear of the unknown 

Physicians do not argue that CT and MRI scans are of tremendous benefit in diagnosing or ruling out illnesses, particularly when patients have symptoms of cardiovascular disease or cancer.

But when a patient has no symptoms, the benefits are much less clear, and the question of potential harm vs. benefit is raised. Illes says asymptomatic people appear to be the imaging industry’s primary advertising target.

Such people may be needlessly exposing themselves to radiation and high cost. Furthermore, there is little evidence that the images will actually improve their chances of a longer life.

Messages preying on consumers’ fears about their health were found in nearly half of the ads and brochures, and all of the ads and brochures included images and messages about the peace of mind the scans can deliver, as well as the potential to save customers’ lives.

Illes says messages included testimonials from other customers who credited the companies with everything from reassuring them about their health to finding "a ticking time bomb in my body."

There’s no denying the growing popularity of the scans among consumers. In a study published last year in the Journal of the American Medical Association, researchers asked 500 people a hypothetical question: Which would they prefer — a free full-body scan or $1,000 in cash? Seventy-three percent of those surveyed chose the scans.

The Stanford research followed up on earlier work by Illes and her colleagues, who reported in 2003 on the lack of medical profession guidelines for appropriate scanning, while documenting the rapid growth of the direct-to-consumer scanning business. It identified 88 such imaging centers nationwide, and at that time Illes noted that, since the research had been completed, some centers had closed their doors, but 48 more centers had opened.

But much of the medical establishment — including the American Cancer Society, Food and Drug Administration, and American College of Radiology, among others — does not endorse scans, full-body or otherwise, for people without symptoms. They say the tests often find harmless irregularities that lead to unnecessary, expensive, sometimes invasive procedures.

Radiation risk shouldn’t be ignored

Illes and her colleagues at Stanford are not alone in recent warnings about potential safety concerns involved with voluntary scanning.

Authors of a study conducted in 2004 by Columbia University in New York City said the risk of cancer from a single full-body CT scan is small, but not negligible, and the risks to people who partake in elective annual scans are higher.

The Columbia study, published in the September issue of Radiology, reported that the radiation dose from a full-body CT scan "is comparable to the doses received by some of the atomic-bomb survivors from Hiroshima and Nagasaki, where there is clear evidence of increased cancer risk," according to David J. Brenner, PhD, DSc, lead author of the study and professor of radiation oncology and public health at Columbia. Brenner pointed out that researchers studied low-dose atomic-bomb survivors, not high-dose survivors.

The researchers estimated cancer mortality risk associated with single and multiple full-body CT scans by comparing A-bomb cancer mortality data with the calculated effective radiation dose from a full-body scan. The dose from a single full-body CT is only slightly lower than the mean dose experienced by groups of A-bomb survivors, in whom significant increases in cancer risk are seen. The effective dose of radiation delivered during a full-body CT exam is nearly 100 times that of a typical screening mammogram, he says.

The Columbia study found that a 45-year-old who underwent one full-body CT screening would have an estimated lifetime cancer mortality risk of approximately 0.08%, which would produce cancer in one in 1,200 people. However, a 45-year-old who has annual full-body CT scans for 30 years would accrue an estimated lifetime cancer mortality risk of about 1.9%, or almost one in 50.

The Columbia report considered risk only for asymptomatic adults who elect to undergo high-tech checkups; however, Brenner stressed that the risks to people who are referred for CT exams by their physicians for medical diagnosis are far outweighed by the benefits of early detection of potentially serious disorders.

The controversy surrounding elective full-body CT screening has been focused primarily on disease detection vs. risk of false-positive findings, while neglecting the potential radiation risks associated with CT scans. CT delivers much larger radiation doses to the organs than do conventional X-rays. (See Estimated Radiation Doses.) Columbia researchers noted different CT scanners produce different doses and, consequently, different risks. Full-body CT protocol is not standardized, so radiation exposure may vary among centers.

In addition to the radiation risks demonstrated in the Columbia research, false-positive findings from an elective full-body CT may cause the consumer to undergo expensive, stressful, follow-up testing, Brenner says.

The Stanford team of researchers urged standardization of full-body CT protocol and guidelines for advertising to consumers, much like pharmaceutical companies ads encouraging for consumers to "ask your doctor."


  • David J. Brenner, PhD, DSc, Professor of Radiation Oncology and Public Health, Columbia University, 630 W. 168th St., New York, NY 10032. Phone: (212) 305-9930.
  • Judy Illes, PhD, Senior Research Scholar and Director of Neuroethics, Stanford Center for Biomedical Ethics. E-mail: Phone: (650) 724-6393.