Post

Assessment of Radiofrequency-Induced Heating in Multi-Configuration Passive Medical Devices for MR Conditional Labeling

This guidance provides recommendations for assessing radiofrequency (RF)-induced heating in multi-configuration passive medical devices in MR environment. It applies to both multi-component and single-component passive devices with various dimensions and shapes that are intended for MR Conditional labeling. Active devices are excluded from the scope.

  1. Define clear MR Conditional scan conditions for labeling
  2. Establish heating acceptance criteria with scientific rationale
  3. Document all possible device configurations comprehensively
  4. Develop and justify methodology to reduce configurations to testable subset
  5. Conduct RF-induced heating assessments using validated methods
  6. Perform uncertainty analysis for all results
  7. Submit pre-submission for complex multi-component devices
  8. Consider using statistical sampling methods to reduce test configurations
  9. Validate computational models if used
  10. Document and justify all decisions in configuration selection process

Key Considerations

Non-clinical testing

  • Conduct in vitro temperature measurements according to ASTM F2182
  • Use computer modeling to determine temperature and/or local SAR
  • Report peak temperature rise over 15-minute RF exposure
  • Validate computational models against measurements
  • Provide uncertainty analysis for all measured/computed results

Labelling

  • Define MR Conditional scan conditions (field strength, SAR levels, coil types, landmark position, scan area)
  • Provide clear constraints in MR Conditional labeling if needed

Safety

  • Establish heating acceptance criterion based on benefit-risk considerations
  • Consider device dimensions and resonant effects
  • Evaluate device geometry impact on heating
  • Assess all possible component configurations
  • Consider surface properties and device construction
  • Evaluate worst-case configurations for each MR environment

Other considerations

  • ASTM F2182: Standard Test Method for Measurement of Radio Frequency Induced Heating On or Near Passive Implants During Magnetic Resonance Imaging

Original guidance

  • Assessment of Radiofrequency-Induced Heating in Multi-Configuration Passive Medical Devices for MR Conditional Labeling
  • HTML / PDF
  • Issue date: 2016-03-22
  • Last changed date: 2019-02-09
  • Status: FINAL
  • Official FDA topics: Physical Medicine, Errors, Orthopedic, Nose & Throat, Gastroenterology-Urology, 510(k), Premarket, Ear, Radiology, Investigational Device Exemption (IDE), Safety - Issues, Ophthalmic, Medical Devices, Obstetrical & Gynecological, Cardiovascular, Labeling, General Hospital & Personal Use, General & Plastic Surgery, and Problems, Premarket Approval (PMA), Anesthesiology, Dental, Neurological
  • ReguVirta summary file ID: 7f13b99210e24d683756e4ebec4ddd64
This post is licensed under CC BY 4.0 by the author.