Common Medical Scan ‘Routinely’ Delivers Excess Radiation, May Cause 36,000 Cases of Cancer a Year

Mar. 15, 2025

Stock image of a CT scanner.Photo:Solskin/Getty

Solskin/Getty

CT scans ‘routinely’ deliver up to three times the radiation they should, which can lead to 36,000 cases ofcancera year.

“In the ninety million CT scans performed annually in the U.S., many patients still routinely receive radiation doses two or three times what they should,” Dr. Rebecca Smith-Bindman, a University of California San Francisco professor in residence of epidemiology, biostatistics, obstetrics, gynecology and reproductive medicine, said in a release fromUCSF.

CT (short for computed tomography, and often pronounced as “cat”) scans use a mix of X-ray and computer technology to provide detailed images of the body,John Hopkins Medicineexplains, adding that “the amount of radiation dose used in a CT scan is small.”

Stock image of an older man going into a CT scanner.peakSTOCK/Getty

peakSTOCK/Getty

But as Smith-Bindman says in the university’s statement, radiologists are defaulting to using higher radiation doses when a lower dose would suffice; while the higher doses generally mean more detailed scans, they’re not always required for the specific diagnosis.

When testing approximately 48,000 CT machines in 17 hospitals, Smith-Bindman’s research found that 30% of the scanners emitted too high a radiation dose — and image quality was never a concern, according to the university’s statement.

As the university’s statement says, this excess radiation, “will lead to cancer in a small percentage of patients, approximately 36,000cancersevery year. This means that CT causes two percent of annualcancer, and we can reduce that risk substantially without reducing the value of the scans.”

Stock image of an older man talking with his doctor.Getty

Getty

Her team has created software that will be provided,free of charge,to hospitals going forward. As the university’s statement says, “No one intentionally harms their patients; they just haven’t been paying attention to radiation dose.”

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source: people.com