How large a dose of radiation is given off by the average CAT scan?

Question

I once broke my leg and was given a CAT scan, even though a regular X-ray had revealed it to be a clean break. I was distraught on finding that the machine seemed to be on for five to ten minutes. Even one still picture seems to contain much more gamma radiation than would be taken in due to natural exposure by the body.

I later asked this question of an employee of a local synchrotron plant, which professes to specialize in concentrating beams of radiation so that they only hit a very tiny and minimal part of the body, thus doing less damage. The employee said he did not know because he was not a health care professional.

I would like to know the answer expressed in commonly used units of radiation.

Answer 1

Gamma radiation is not the same thing as X-rays. An average CT scan would give you 1000mRem of exposure. Do you know for sure the machine's beam was active for the whole five to ten minutes. If it was then your dose is signifacantly higher. The tech was negligent. The average lenght of exams can be done in one breath hold now. I got the following information from http://www.school-for-champions.com/health/xrays.htm The amount of radiation received in a CAT Scan is about 10 mSv or 1000 mrem. That means that a you could safely get 5 CAT Scans in a year to increase the changes of cancer 1%. That is as much as you would get from natural radiation in 3 years.

Answer 2

I remember reading that it is about 1/20th the dose of radiation you'd receive flying on a plane.