Psychiatric-Mental Health Nurse Practitioner Exam

Which of the following imaging techniques cannot be used for patients with metal objects such as a pacemaker?

1. MRI

2. CT Scan

3. PET Scan

4. EEG

The correct answer is: MRI

The choice of MRI as the imaging technique that cannot be used for patients with metal objects such as a pacemaker is grounded in the fundamental principles of how MRI works. MRI uses powerful magnets and radio waves to create detailed images of organs and tissues inside the body. The strong magnetic field can interact with metal objects, potentially causing them to move or heat up, which poses significant risks to the patient, including displacement of devices like pacemakers or alterations in their functioning. Pacemakers, being electronic devices, are particularly sensitive to the magnetic fields generated during an MRI scan, leading to serious complications or even failure of the device. In contrast, other imaging modalities such as CT scans, PET scans, and EEGs do not utilize strong magnetic fields. CT scans use X-rays, which do not interfere with metal objects. PET scans are based on radioactive tracers and do not involve a magnetic field, and EEGs measure electrical activity in the brain through electrodes placed on the scalp, which are safe to use with patients who have metal implants. Therefore, the significant risk associated with MRI in the presence of metallic objects makes it the correct choice in this scenario.