A CT scan exposes a person to significantly higher radiation than airport security scanners. While both use ionizing radiation, the amount and purpose differ greatly. CT scans involve X-rays that pass through the body to create detailed internal images, requiring doses that are thousands of times higher than the very low-level radiation used in airport scanners designed only to detect objects on or inside luggage or on the body surface.
To put it simply, a typical CT scan delivers radiation measured in millisieverts (mSv), often ranging from about 1 to 10 mSv depending on the type of scan and body part imaged. For example, a chest CT scan might expose a patient to around 7 mSv. In contrast, airport security scanners use milligray or microgray levels of radiation, which are roughly a thousand to a million times lower than medical imaging doses. The radiation from airport scanners is so low that it is considered negligible in terms of health risk.
The reason for this huge difference lies in the purpose and technology of each device. CT scans must penetrate the body deeply and produce high-resolution cross-sectional images to help diagnose medical conditions like fractures, tumors, or internal bleeding. This requires a substantial amount of X-ray energy. Airport scanners, on the other hand, only need to scan the surface or very shallow depths to detect concealed items, so they operate at extremely low radiation levels.
Radiation from CT scans is ionizing, meaning it can damage DNA and cells, potentially increasing cancer risk over time, especially with repeated exposure. This is why medical professionals follow the ALARA principle—keeping radiation “As Low As Reasonably Achievable”—to minimize unnecessary scans and optimize dose. Despite the higher radiation, CT scans provide critical diagnostic information that often outweighs the small risk. Airport scanners, with their minimal radiation, pose virtually no measurable risk.
In summary, the radiation dose from a CT scan is vastly higher—by thousands to millions of times—than that from airport security scanners. The medical benefits of CT scans justify their higher radiation exposure, while airport scanners are designed to be safe for frequent public use with negligible radiation impact.