MRI examinations are practically risk-free. However, due to the magnetic field some objects containing metal may be attracted and overheat.
The following risk groups are therefore usually excluded from an MRI examination:
- Patients with metallic implants such as pacemakers, defibrillators, or drug pumps that are not MRI-approved
- Patients with vascular clips in the head placed after brain surgery (e.g., after Brain Aneurysm bleeding/ Hemorrhagic Stroke)
- Pregnant patients at certain weeks/trimesters
In contrast, the examination is usually harmless for patients with:
- Recent bone and joint implants (usually made of Titanium or other non-magnetic material)
- Coronary-stents
- Vascular clips (small metal clips used to close vessels e.g., after bypass operations)
Ultimately, nerve stimulation may also occur due to electromagnetic impulses (peripheral nerve stimulation). In extremely rare cases, the examination may cause tingling or slight muscle twitching.