What should you know about an MRI or CT scan at a radiology department?

CT uses X-rays and computer processing to produce cross-sectional views, while MRI uses a magnetic field and radio waves. The choice depends on the body area, the clinical question, timing and any safety considerations.

Some examinations use an injected or swallowed contrast agent to make selected tissues, blood vessels or a suspected abnormal area easier to distinguish. A radiographer checks relevant medical details before the examination and explains positioning, movement and breath-holding instructions.

Follow the department's instructions about food, drink and medicines. Tell the team about pregnancy or possible pregnancy, kidney problems, allergies, implanted devices, metal fragments and difficulty remaining still. Remove metal objects before an MRI and mention anxiety about enclosed spaces so practical support can be discussed.

Bring the referral information and previous images if requested. After the scan, the radiologist reviews the images and sends a report to the clinician who arranged the examination; the department may not be able to interpret the findings immediately.

Contact the radiology team promptly if you develop breathing difficulty, facial swelling, widespread hives or severe dizziness after contrast. Seek urgent medical help for sudden weakness, trouble speaking, new loss of vision or a severe rapidly developing headache, whether or not imaging has been arranged.

Ask which scan is planned and what question it is intended to answer. You can also ask whether contrast is needed, how to prepare, when the report will reach your clinician and what the next step may be if the images need further assessment.