Radiation Safety
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​What are x-rays?

X-rays are used in many medical imaging procedures, including CT.

  • X-rays are a form of invisible energy that can pass through the body.
  • X-rays are a source of radiation.
  • X-rays allow us to look inside the body to find disease or broken bones or other problems.

Can medical x-rays cause harm?

Your health is important to us and x-rays are only taken if needed.


  • There is a small risk with any medical drug, test, or therapy.
  • X-rays might very slightly increase cancer risk.

When a doctor requests an x-ray or CT exam, it means in their expert opinion the benefits gained from the imaging information outweighs any risk from the radiation.

Do we receive radiation from natural sources?

Yes. Natural sources include:

  • Sun
  • Soil
  • Food

X-ray radiation dose is measured using millisieverts (mSv) just like temperature is measured using Celsius (°C).

Background radiation (the radiation in our environment) varies throughout the BC Interior. Within the Interior Health Region you get between 1.8 to 7.9 mSv per year depending on where you live.

How much radiation do we get from x-rays?

Different exams require different amounts of radiation. More radiation is required to image thicker body parts. CT gives more detail and generally uses more radiation than x-ray exams.

​Exam ​Radiation Dose ​Equivalent Background Radiation
​Knee x-ray ​0.01 mSv ​1-2 days
​Chest x-ray ​0.02 mSv ​2-4 days
​Lumbar Spine x-ray ​0.2 mSv ​1-6 weeks
​Mammography ​0.4 mSv ​1-3 months
​Head CT ​2.1 mSv ​3-14 months
​Chest CT ​9.2 mSv ​1-5 years
​Abdomen/Pelvis CT ​12.7 mSv ​1.6-7 years

Is there a limit to the amount of radiation I can receive from medical imaging?

No, there is no limit to receiving necessary x-ray or CT exams. As long as the exam is clinically appropriate, the health benefits of the x-ray diagnosis far outweigh the x-ray dose risks.

Nevertheless, Interior Health employees are always trying to reduce x-ray and CT dose through radiation safety and quality assurance initiatives. 

How much risk is there from medical radiation?

There is very little risk from medical radiation. The main concern is the possibility of future cancer from the x-rays. The risk of cancer from an x-ray exam is a fraction of a percent per exam, and might be zero. This is very small compared to the risk of naturally occurring cancer, which is between 14 and 40 %. The dose you have received from past x-rays will not increase your chance of developing cancer from the current exam.

Are there alternatives to x-ray exams?

In some cases, yes. Ultrasound (US) and Magnetic Resonance Imaging (MRI) do not use x-rays and do not increase cancer risk. However, US and MRI may not provide the diagnostic information needed. Doctors know the best exam to perform to maximize the health benefit to patients.

Can children have x-ray exams?

Yes. The doctor who requests the x-ray determines if the health benefit of the exam outweighs any potential risks from radiation.

The amount of radiation used for children is lower than what is used for adult exams. Your doctors and Interior Health employees take extra precautions when performing x-rays on children.

Can pregnant women have x-ray exams?

Yes. The requesting doctor, x-ray staff, and radiologists take great efforts to identify pregnant patients. In most cases the health benefit of having the x-ray exam far outweighs the potential risk to the unborn child. Your doctors and Interior Health employees take extra precautions for both pregnant women and women of childbearing age. Please see the pregnant patient pamphlet for more information.

Be sure to notify your doctor or x-ray technologist if you are pregnant.


As a step towards reconciliation, Interior Health acknowledges the land that we live, work, and play on as the traditional territories of the Dakelh Dene, Ktunaxa, Nlaka’pamux, Secwepemc, St’at’imc, Syilx and Tsilhqot’in peoples. It is with humility that we continue to strengthen our relationships with the First Nation, Métis, and Inuit peoples of the interior.
MoH     PCQO