NEW YORK, April 15: US researchers are raising concerns over the potential health risks linked to the increasing use of CT (computed tomography) scans — a common diagnostic tool that uses X-rays to create detailed images of the body. While these scans play a vital role in detecting diseases, experts say the radiation exposure they involve could elevate cancer risks, particularly with frequent or unnecessary use.

CT scans differ from MRI (magnetic resonance imaging) scans, which use magnets and radio waves instead of radiation. Though both machines resemble tube-like structures and produce high-resolution images, the radiation used in CT scans belongs to the high-energy end of the electromagnetic spectrum — the same range that includes ultraviolet (UV) rays and gamma rays. This type of "ionizing" radiation has enough energy to damage tissue at the molecular level, potentially leading to cancer.

"CT can save lives, but its potential harms are often overlooked," said Dr. Rebecca Smith-Bindman, a radiologist at the University of California San Francisco and lead author of the study.

The research modeled cancer risk in 61.5 million U.S. patients who had undergone CT scans, estimating that around 103,000 cancer cases could eventually result from the radiation exposure over their lifetimes. This would represent about 5% of the annual cancer diagnoses in the U.S., assuming current scanning rates continue.

CT scan usage has risen by approximately 30% since 2007, with older adults — especially those aged 60 to 69 — being the most frequent recipients. The study found abdominal and pelvic CT scans posed the highest risk for adults, while head scans were most concerning for children. Infants scanned before their first birthday faced a tenfold higher risk of developing cancer compared to older children.

“Our estimates put CT on par with other significant risk factors, such as alcohol consumption and excess body weight,” Dr. Smith-Bindman noted. “Reducing the number of scans and minimizing radiation doses could save lives.”

She emphasized that many scans are performed unnecessarily, including those ordered for mild symptoms like headaches or respiratory infections. Additionally, patients often receive higher doses of radiation than required, further increasing their health risks.

Other experts echo these concerns. Dr. Pradip Deb, a radiation safety specialist at RMIT University in Australia, who was not involved in the study, agreed that high-energy radiation is a known carcinogen. However, he cautioned that not every individual exposed to radiation will develop cancer, and personal risk varies.

“Radiation is a well-established cause of cancer, but we must balance that knowledge with the benefits CT scans provide,” said Dr. Deb. “They are essential in diagnosing conditions that can significantly improve a patient’s quality of life.”

He added that while the risks should not be ignored, patients should not panic. Instead, medical providers must focus on using CT scans only when truly necessary and opt for lower-dose or non-radiation alternatives where available.

Ultimately, researchers call for more responsible and regulated use of CT scans in healthcare to minimize avoidable harm while continuing to harness their life-saving benefits.