[MRI safety : Principles, risks and protective measures]

Area of Science:

• Medical Imaging Physics
• Biomedical Engineering
• Radiological Safety

Background:

• Magnetic resonance imaging (MRI) offers significant diagnostic advantages but presents inherent safety risks.
• These risks are primarily associated with the powerful static magnetic fields and alternating electromagnetic fields (high-frequency and gradient fields).
• Uncontrolled ferromagnetic objects and metal implants within the MRI environment pose particular dangers, including projectile effects and tissue heating.

Purpose of the Study:

• To identify and elucidate the specific safety risks associated with magnetic resonance imaging (MRI) procedures.
• To detail the potential hazards posed by static magnetic fields, high-frequency (HF) fields, and gradient fields.
• To emphasize the importance of safety measures in mitigating MRI-related risks.

Main Methods:

• Review of established principles of magnetic resonance imaging physics.
• Analysis of documented incidents and potential hazards related to ferromagnetic materials and implants in MRI.
• Examination of the biophysical interactions between electromagnetic fields and biological tissues or conductive materials.

Main Results:

• Strong static magnetic fields can cause uncontrolled movement of ferromagnetic objects, leading to severe injuries.
• Alternating electromagnetic fields (HF and gradient) can induce tissue heating, nerve stimulation, and overheating of conductive materials.
• Metal implants may interact undesirably with the MRI system, causing heating or malfunction.

Conclusions:

• The application of MRI necessitates a thorough understanding of its associated safety risks.
• Appropriate safety measures, including clear labeling, specialized training for personnel, and automated monitoring systems, are crucial.
• These safety protocols can effectively minimize the risks posed by MRI to patients and staff.