It is commonly thought that the extra risk of any one person developing a fatal cancer from a typical CT procedure is about 1 in 2,000 (2). In contrast, the lifetime risk of dying from cancer in the U.S. population is about 1 in 5 (3).
2. U.S. Food and Drug Administration (August 2009). What are the Radiation Risks from CT? Retrieved July 19, 2013.
If your doctor orders a CT, just ask him whether it can be replaced by ultrasound or MRI. I did it successfully twice. Once for myself and once for my son. Both results were normal. Everyone is happy.