A nurse is reviewing a client scheduled for an MRI of the cervical spine. Which finding is a contraindication to the procedure?

• A. The client has a pacemaker.
• B. The client has a history of glaucoma.
• C. The client wears a hearing aid.
• D. The client has a prosthetic knee joint.

Answer: (A)

The main concept here is MRI safety with implanted devices, especially pacemakers. The strong magnetic field and radiofrequency energy used in MRI can interact with a pacemaker in dangerous ways: it can cause inappropriate sensing or pacing, reprogram the device, or lead to lead heating that can injure heart tissue. Because of these risks, a pacemaker is a contraindication to undergoing an MRI of the cervical spine unless the device is explicitly labeled MRI-conditional and specific safety protocols are followed with cardiology oversight.

The other findings don’t pose the same absolute risk. Glaucoma isn’t an MRI safety issue for the eye in itself. A hearing aid can usually be removed before the scan to prevent device interference or damage. A prosthetic knee joint is typically considered safe for MRI, though any metallic implant can sometimes create image artifacts; it doesn’t generally prevent the scan.