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.
Recommended Actions
- Define clear MR Conditional scan conditions for labeling
- Establish heating acceptance criteria with scientific rationale
- Document all possible device configurations comprehensively
- Develop and justify methodology to reduce configurations to testable subset
- Conduct RF-induced heating assessments using validated methods
- Perform uncertainty analysis for all results
- Submit pre-submission for complex multi-component devices
- Consider using statistical sampling methods to reduce test configurations
- Validate computational models if used
- 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
- Define and describe all possible device configurations (CCall)
- Use scientific methods to reduce configurations to a manageable test set (CCtest)
- Consider factors like device dimensions, geometry, components, surface properties
- Assess heating for devices partially inside/outside patient body
- Consider electrical and thermal properties of materials
Relevant Guidances
- Testing and Labeling of Medical Devices for Magnetic Resonance (MR) Environment Safety and Compatibility
- Premarket Notification Requirements for Magnetic Resonance Diagnostic Devices
Related references and norms
- 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
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