CT Scans and Cancer Risk: A Mount Sinai Radiologist Explains
CT Scans and Cancer Risk: A Mount Sinai Radiologist Explains
health. mountsinai. org / blog / ct-scans-and-cancer-risk-a-mount-sinai-radiologist-explains / May 7, 2025
You may have seen headlines recently about a link between CT( computed tomography) scans and cancer due to radiation exposure. CT scans project X-rays into the body to produce detailed images and are often necessary in situations where a medical diagnosis needs to be made quickly. While they are generally considered safe, multiple CT scans over time pose a small increase in cancer risk.
To keep you safe, radiologists take steps to reduce your exposure as much as possible.
In this Q & A, Bradley Delman, MD, MS, a neuroradiologist and Vice Chair of Quality at Mount Sinai, explains the benefits of CT scans and how radiologists work to reduce the risks.
What is a CT scan, and why is it important for diagnosing health conditions? CT is a powerful tool that uses carefully focused beams of radiation to generate images inside the body. These scans enable doctors to see structures in three dimensions to diagnose a wide variety of conditions including strokes, bleeding, infections, tumors, and traumatic injuries. Sometimes dye is injected into the veins to improve visualization of blood vessels, tumors, and inflammation. These scans have become invaluable for emergency situations and presurgical planning.
Bradley Delman, MD, MS
Can CT scans increase my risk of developing cancer from radiation exposure? CT machines do expose patients to ionizing radiation, which over time can damage DNA. Fortunately, DNA is believed to repair itself in most instances. DNA that does not get repaired can slightly increase your long-term risk for cancer. Cumulative exposure from multiple CT scans over time may cause DNA damage to accumulate, and that is also believed to increase cancer risk.
It’ s important to note that we only scan when necessary and that we use the lowest radiation doses necessary for diagnosis. Scanners are getting even more efficient at this. Ultimately, we must compare the risks and the benefits, and it is more essential to