Which statement about MRI safety is true?

• A. It does not use ionizing radiation.
• B. It uses ionizing radiation.
• C. It requires injections of radioactive tracers.
• D. It cannot be used to image the brain.

Answer: (A)

MRI safety hinges on how the technology actually generates images. It uses a powerful magnetic field and radiofrequency energy, not ionizing radiation. That means, unlike X-ray or CT scans, MRI does not expose patients to ionizing radiation. This is particularly important for children who may need multiple scans. In MRI, contrast agents, when used, are typically gadolinium-based and are not radioactive, so you don’t inject radioactive tracers as you would in nuclear medicine or PET imaging. MRI is also excellent for brain imaging, so saying it cannot image the brain isn’t correct. Other safety considerations with MRI involve ferromagnetic implants or severe claustrophobia, rather than radiation exposure.