FDA qualifies tool for predicting temperature rise when orthopedic implants enter MRI scanners
- The U.S. Food and Drug Administration has qualified a tool made by NEVA Electromagnetics to predict the temperature rise when patients with certain orthopedic implants undergo magnetic resonance imaging (MRI).
- By qualifying the technology under its Medical Device Development Tools (MDDT) program, the FDA has cleared sponsors to use the simulation in the development and evaluation of metallic femoral nails.
- The tool can help sponsors identify device designs that cause the biggest heat rise, and as such are least suitable for use in people who may undergo MRI, and determine the conditions under which an implant can safely be exposed to the radiofrequency fields generated during the scans.
The FDA classifies some devices as “MR unsafe” and prohibits them from entering the scanner room. If the device is implanted, the patient cannot undergo MRI. Other devices are classified as “MR conditional” and can only enter the scanner room under specific conditions set out in the product label.
The latest MDDT, a FDA program designed to make evidence generation more predictable and efficient, is intended to help sponsors assess the conditions under which an implant can safely enter a scanner room, and to predict the worst possible designs. Tweaking variables such as implant size, configuration and orientation in the simulation changes the predicted temperature rise.
Sponsors need to minimize the temperature increase when metallic femoral nails are exposed to MRI radiofrequency. After reviewing the evidence, the FDA has determined that NEVA Electromagnetics’ computational tool can support work toward that goal.
The tool simulates the complete MRI environment. The FDA found the tool predicts, with an uncertainty of 33%, the temperature distribution and change over time along an implant exposed to an MRI scanner. The analysis is based on a comparison of experimental data and simulation results.
Now the FDA has qualified the tool, sponsors can include the MDDT number in marketing applications that rely on data generated by the simulation. The use of qualified tools is intended to make it clear that the FDA accepts MDDT assessments in support of safety, effectiveness or performance, increasing predictability for medical device sponsors.