A new study is raising eyebrows about a technology most Americans consider routine: the CT scan. While these scans are often lifesaving, researchers now estimate that radiation from CT scans performed in 2023 could potentially lead to over 100,000 future cancer cases in the U.S.
The study, led by epidemiologist Rebecca Smith-Bindman of UCSF, suggests that low doses of ionizing radiation from CT scans—though minimal for any one person—could collectively account for up to 5% of all new U.S. cancer diagnoses. The rise in CT usage is dramatic, with a 30% increase since 2007 and roughly 93 million scans estimated in 2023 alone.
Here’s the concern: while high doses of radiation are a known cancer risk, the danger of low-dose exposure—like that from CT scans—remains theoretical but plausible. Data from atomic bomb survivors and nuclear incidents show that even modest radiation levels can slightly raise cancer risk over a lifetime.
Children and infants are especially vulnerable, particularly when scans are done under the age of one. Female patients also appear to have a higher susceptibility to thyroid cancers linked to early-life exposure.
But not all experts are sounding alarms. Dr. Cynthia McCollough, a CT imaging specialist, emphasizes that the benefits outweigh the risks when scans are medically necessary. In one large national trial, low-dose CT scans reduced lung cancer deaths by 20% in high-risk individuals.
Still, the takeaway is clear: CT scans should be used with discretion. When other radiation-free methods like ultrasound or MRI are viable, they should be considered.
As medical imaging becomes more common, awareness around radiation exposure—and avoiding unnecessary scans—could be key to minimizing long-term risks.
