Which implanted device is commonly considered a safety hazard in MRI?

• A. Scissors
• B. Pacemaker
• C. Endocavity coil
• D. Oxygen tanks

Answer: (B)

The main idea is MRI safety for implanted devices. The strong static magnetic field, plus gradient fields and RF energy in MRI, can interact with electronic implants and their leads, causing movement, heating, or interference with device function. A pacemaker is particularly risky because its generator and pacing leads can misread signals, change pacing behavior, or inhibit pacing, and the leads can heat at their tips, potentially injuring tissue or causing inappropriate rhythms. Modern devices exist that are labeled MR-conditional under specific conditions, but historically pacemakers are the most common implanted-device safety hazard in MRI. The other options are not implanted devices, so they don’t carry the same implanted-body risk in the MRI environment.