Explaining the Safety of Radiation Used During a CT Scan

You may be shocked to find out about all the sources of radiation that are around us each and every day. What’s more shocking is the amount of radiation that we may be absorbing. 

Illustration depicting radiation from various household sourcesIonizing radiation, which can damage the cells or DNA in our bodies, is all around us. Comparing that reality to a typical CT Scan is useful for explaining the safety of the amount of radiation used during an X-ray or CT Scan.

A Beautiful and Typical Day in the Neighborhood

Mr. Rogers never talked about the radiation in his neighborhood “back in the day.” Today it may still be a beautiful day, but we are bombarded with radiation from many sources. Our smart TVs and computer screens all emit radiation, but even rocks and dirt have radioactive particles. Not to mention, they are in our food, our bones, and in the air.

Let’s keep going. We receive cosmic rays from outer space that become exacerbated when we fly or if we are located up in the mountains. Let’s not forget power plants that run on coal and nuclear fuels. These revelations may make you want to stay safely in bed with your head under the covers. So, do we need to worry about the safety of radiation used during a CT Scan?

Some Radiation Comparisons

The fact is that yes, there are more medical imaging tests run today than there were even thirty years ago, and some tests emit more radiation than others. Another fact is that the benefits from such medical tests can far outweigh any risks. Lastly, radiologists are careful to use the least amount of radiation to perform the test.

The units that measure radiation are known as millisieverts (mSv). The naturally-occurring background radiation we receive annually contains 3 millisieverts.

Some approximate comparisons are as follows:

  • A spine X-ray emits 1.5 mSv equal to 6 months background radiation
  • A CT Computed Tomography of the head emits 2 mSv equal to 8  months background radiation
  • A chest X-ray emits .1 mSv equal to 10 days background radiation
  • A dental X-ray emits .005 mSv equal to 1 day background radiation
  • A mammogram emits .4 mSv equal to 7 weeks background radiation
  • A heart CT (computed tomography angioplasty) emits 12 mSv equal to 4 years background radiation

CT scans will always deliver higher doses of radiation due to the cross sectional images this particular test takes. Inversely, children being tested will have lower doses, and these comparisons will vary from above.

Hospitals and imaging centers use the principle of ALARA which means As Low As Reasonably Achievable. This implies that they will use the lowest dose possible to achieve the proper diagnosis.  

Are You Safe?

With more tests being ordered and more CT scans being performed, what exactly is your risk for developing cancer? The short answer is that whether you are being tested for kidney stones or a cardiac blockage, the benefits of imaging tests far outweigh any risk of radiation exposure.

If you have concerns about accumulated radiation exposure, ask your provider if there are other alternatives such as an MRI or ultrasound to give you the information you need and the proper diagnosis. Voicing your concerns to your provider will also help to ease your mind and find a solution that is best for you.

Category: Radiology

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