Experts urge perspective, saying the risk per child remains low.

After a hard fall, a computed tomography (CT) scan can seem like a lifeline. In minutes, the scan can rule out a brain bleed or another hidden injury. The technology now anchors pediatric care, guiding decisions on concussions, appendicitis, and cancer.

A new study found that CT scans may carry hidden costs. About one in 10 blood cancers among the children and adolescents studied – roughly 3,000 cases – may be attributable to imaging radiation, according to one of the largest studies to date linking medical radiation to childhood leukemia and lymphoma.

The risk to any one child is small, but across millions of patients it adds up.

For families, those numbers can sound stark. However, radiologists suggest the immediate danger of missing a ruptured appendix or brain bleed usually outweighs the distant risk of radiation. Concern around the issue is sharper in the United States, where children are scanned far more often than their peers abroad, sometimes for reassurance rather than necessity.

The Study

Published in The New England Journal of Medicine, the study tracked imaging histories of nearly 4 million children in the United States and Canada, linking them to cancer registries. Investigators followed patients into early adulthood to see how exposure related to disease.

Having one or two head CTs nearly doubled the odds of developing a blood cancer, and multiple scans raised the risk more than threefold. Nearly 3,000 children developed leukemia, lymphoma, or related cancers.

“A tripling of the risk of cancer is a very important risk factor that we need to take into consideration when ordering scans, because cancer for a child and their family is often devastating,” Dr. Rebecca Smith-Bindman, the study’s lead author and a University of California, San Francisco radiologist, told The Epoch Times in an email.

Children were followed until age 21. “The vast majority of cancers that will develop occur many years after exposures,” Smith-Bindman said.

The findings show an association, not proof of cause and effect. To limit bias, the authors excluded scans done just before a cancer diagnosis. However, some critics have pointed out that children who receive CTs often differ from those who do not in ways that can influence cancer risk. Even so, the study’s size and methods lend weight to longstanding concerns about radiation in young patients.

Understanding the Risk

To put the findings in perspective: In this study, about 14 in 10,000 children developed cancer without imaging. Imaging nudged that number up slightly, depending on dose. Two head CTs may add about 25 per 10,000.

“Very few children develop cancer,” Cynthia McCollough, a medical physicist at Mayo Clinic, told The Epoch Times in an email. If a scan will help diagnose or treat a child, the expected benefit outweighs it, she added.

The youngest children faced the highest risk, both because their developing tissues are more vulnerable to radiation and because they have more years ahead for cancer to emerge. Risk was highest in the immediate years after exposure but lingered into young adulthood, with most cancers appearing years after the initial scan.

McCollough noted that many of the exams occurred before 2004, when pediatric doses were higher. With today’s techniques, comparable exams generally deliver lower doses, suggesting the risks reported may overstate current danger.

However, practice varies. Children’s hospitals routinely tailor CT settings for smaller bodies, while many other facilities—especially those without pediatric expertise – use less child-specific protocols, leading to higher and more variable doses. That variability is one reason specialists emphasize the same principle: the right test, at the lowest dose, when the result will change care.

Against that backdrop, some experts say the study does not change current guidance. “CT is lifesaving,” Dr. Donald Frush, a pediatric radiologist at Duke, told The Epoch Times. “This study shows an association, not causation, and when people conflate the two, it can inject harm and alarm into an already complex medical decision.”

Between 2 Risks

At the bedside, parents rarely think in probabilities. They weigh fear against hope and the ticking clock.

“There may be no risk, or some risk, but we can say it’s small,” Rebecca Milman, a medical physicist, told the Epoch Times. “That makes honest conversations hard when families want to know, ‘How small?’ We can’t quantify it with certainty.”

She recalled patients who declined needed scans out of fear of radiation, a reminder that risk communication can backfire when not properly contextualized. That uncertainty leaves families caught between two dangers: the distant risk of cancer and the immediate risk of missing a life-threatening condition.

If dose is the concern, why not lower it? Radiologists say it isn’t that simple. In some cases, too low a dose blurs the image and risks missed findings.

“If you miss a dangerous finding, that’s a much bigger, immediate risk than the small long-term radiation risk,” Frush said.

America’s Imaging Habit

The United States performs more CT scans than any other country – several times higher than many European nations. The gap reflects more than medical need. Doctors often order extra tests to protect against lawsuits, and patients expect quick, definitive answers.

Nearly half of high-risk specialists admitted ordering unnecessary imaging over the course of a year, according to a JAMA study. Patients add to the pressure. “It’s an American thing,” Frush said. “If doctors don’t do something, patients are disappointed.”

The consequences are predictable. “Research suggests that 30% or more of medical imaging is of low value and does not improve care,” Diana Miglioretti, one of the study authors and professor of biostatistics at the University of California, Davis, told The Epoch Times in an email. Scans may be ordered “just to be safe” when symptoms are minimal and the results won’t alter treatment, exposing children to radiation without benefit.

International standards require that every exam be justified, with benefits clearly outweighing the harms. By that measure, many U.S. scans would not meet the standard.

What Can Change

The answer is not to abandon CT technology, but to use it more deliberately. Some children’s hospitals already tailor doses and favor ultrasound or MRI when possible, yet safeguards remain patchy, especially in community hospitals where most children receive care.

“Clinicians should use the right test, at the lowest dose needed, and avoid repeats,” Miglioretti said.

Parents can help by asking questions: What are we looking for? Is there a safer option?

How will the result change care?

Frush agrees, but notes that radiation is not always the chief worry at the bedside. “We have heard parents say, ‘I am more worried about whether insurance will cover this,’” he said. Risk discussions, he added, should be clear and tied to how the scan will affect treatment.

The hardest decisions often fall in gray areas – a child with routine headaches, vague abdominal pain, or repeated visits for the same complaint. Ultrasound or MRI can often provide answers without radiation exposure.

“Ask an emergency physician if a scan was ‘unnecessary’ and you’ll hear why it felt necessary at 2 a.m. with a sick kid and worried parents,” Frush said.

The deeper safeguard may lie less in protocols than in trust.

“Health care is incredibly personal,” Frush said. “If we reduce it to a formula – only radiation risk, only guidelines – we undermine the covenant between provider and patient. The conversation has to respect the whole picture of care.”

For parents in crisis, the glow of a CT scanner can feel like a promise of safety and relief. The new research does not deny that power. It asks whether we have allowed a lifesaving tool to become reflexive, and whether we can keep the scans that save lives while letting go of those that only add risk.

Written by Sheramy Tsai, , BSN, RN for Epoch Health ~ September 24, 2025