Dr. Greene’s Answer:
A typical x-ray delivers 0.01 mSv (millisievert) of radiation. CT scans give us much more information, but they can also deliver as much radiation as getting 300 regular x-rays — or 600, if the CT scanner has not been adjusted for children! Even though CT scans are a small minority of the total number of x-rays done, in the US they are responsible for about 65 percent of all medical radiation exposure.
In order to understand how this relates to day-to-day radiation exposure, I looked to information from the American College of Radiology. They have found that the average person living in the United States is exposed to about 3 mSv annually from “naturally occurring radioactive materials and cosmic radiation from outer space.”
Read More From This Series:
CT Scan Defined
CT Scan, Ultrasound or MRI?
CT Scan Safety
CT Scans and Radiation Exposure
CT Scan Risks
Higher Risks in Children
Who Should Receive a CT Scan?
X-Ray or a CT Scan?
Alternatives to a CT Scan
When Should a CT Scan be Performed?
Important Tip to Reduce to Radiation
Questions to Ask before Every CT Scan
Other Radiation Exposures
Measures That Radiologists Should Adhere to When Administering a CT Scan
CT Scans and Cancer
When are MRIs not Practical?
What is Ionizing Radiation?
Who are Radiologists?
Last reviewed: February 14, 2008