External Orthopaedic Implants in the Magnetic Resonance Environment: Current Concepts and Controversies

Area of Science:

• Radiology
• Medical Imaging
• Biomedical Engineering

Background:

• Magnetic Resonance Imaging (MRI) is vital for diagnosing spinal trauma and acute injuries.
• Implantable passive orthopedic devices are generally safe for MRI.
• Recent changes in American Society for Testing and Materials (ASTM) terminology have caused provider confusion regarding device safety.

Purpose of the Study:

• To review literature and industry recommendations on the safety of external fixation, cervical immobilization, and traction devices in MRI environments.
• To address safety concerns including radiofrequency-induced heating and magnetic torque.
• To clarify recent ASTM terminology updates impacting MRI safety assessments.

Main Methods:

• Literature review of pertinent studies.
• Analysis of current industry recommendations.
• Examination of safety standards for medical devices in MR environments.

Main Results:

• Most passive orthopedic implants are safe for MRI.
• Radiofrequency-induced heating and magnetic torque are primary safety concerns.
• Lack of consensus exists among radiologists regarding specific devices, especially external fixation and cervical immobilization devices.

Conclusions:

• Standardized institutional protocols are essential for imaging polytraumatized patients with external devices.
• Clarifying ASTM terminology is crucial for consistent MRI safety practices.
• Further consensus and clear guidelines are needed for safe MRI of patients with external fixation, cervical immobilization, and traction devices.