Medical Radiation

Getting the right test

How do I know I’m having the right test?

Your doctor is the one to know the right test for you. Listen closely to what your doctor says, understand the test you’re having and ask if there are other tests or things you can do that don’t use radiation.

Tell your doctor if you’ve had tests in the past that used radiation for diagnosis. Other doctors and dentists who take care of you don’t always know about your other test results.

IDEA: Start a radiation record (link opens in new window)  to keep track of your test history and share it with your healthcare providers.

Here are four types of imaging tests you may be prescribed:

  1. X-ray: An X-ray is most-often used to diagnose cavities, broken bones or respiratory illnesses. It creates a two-dimensional image and uses the lowest dose of the radiation tests. The radiation exposure risk to the body from X-ray procedures varies depending on the part of the body being X-rayed.
X-Ray
  1. Computed tomography (CT): CT scanners create detailed images of the body. These images can show more information compared to an X-ray. Making these images uses a much higher dose of radiation than an X-ray. A CT scan uses between 150 and 1,100 times the radiation of a regular X-ray.
CT
  1. Magnetic resonance imaging (MRI): MRI tests use strong magnets. This test can give different information about parts of the body than the images from X-rays, ultrasounds or CT tests. For example, an MRI exam of a joint can show detailed images of ligaments and cartilage.
    • MRI scanning does not use radiation.
MRI
  1. Ultrasound: An ultrasound exam uses high-frequency sound waves to create images of organs and systems within the body.
    • Ultrasounds do not use ionizing radiation to create images.
Ultrasound

When you talk with your doctor or anyone prescribing a test for you, ask these questions:

  • What is the test you want me to have and does it use radiation?
  • What will you learn from this test?
  • Are there other tests I can get instead that don’t expose me to radiation?
  • Should I have this test even though I have had prior tests that have exposed me to radiation?
  • How will you use this or other tests to treat me?