Because the radiation strikes only a small area, the cancer risk is negligible.
Children are at more risk than adults.
For comparison, a total body exposure of 5 rads of radiation increased the risk of cancer among survivors of the World War II atomic blasts in Hiroshima and Nagasaki. Radiation exposure from medical procedures can vary according to the different machines used across the nation. When most people think of nuclear radiation, they think of atom bombs and fallout, not medical tests. Yet more patients are exposed to radiation from CT scans than any other source, says physicist Fred Mettler of the University of New Mexico. Each scan delivers 2 to 3 rads of radiation.