The FDA has released new guidelines for properly assessing the safety and compatibility of medical devices within MR imaging rooms.
The recommendations apply to implanted devices, technologies fastened or carried by patients such as external insulin pumps, and devices brought into the MR room during clinical care. They do not apply to MR machines or their components.
In addition, the 32-page document lays out safety labeling information that should be part of premarket submissions, as well as key information to be included in test report summaries and completed reports. Its tips include labeling devices as MR Safe, MR Unsafe or MR Conditional and using these and other terminology when testing the safety of devices in MR environments.
“Appropriate testing and analyses, scientific rationale, and labeling, such as well-supported MR Conditional labeling form the basis of adequate mitigations for the unique safety hazards of the MR environment,” said the FDA.
The guidance also discusses methods for addressing medical device-related hazards in MR environments, magnetically induced displacement force, induced heating to tissue adjacent to devices, image artifacts, and reporting results.
One recommendation that appeals to Tobias Gilk, former chair of the American Board of Magnetic Resonance Safety (ABMRS) and founder of the consulting firm, Gilk Radiology Consultants, is that small objects two centimeters or smaller do not pose any significant radiofrequency heating risk to 3.0T MR scanners and lower versions. “This should help reduce the testing and labeling burden for device manufacturers but perhaps more importantly, if this information is promulgated to radiologists, it will help reduce MR exam cancellations of patients with piercings that some providers delay or cancel based on fears of burn injuries," he told HCB News.
Gilk attests, however, that while supportive of the guidelines around MR safety labeling the unintended consequences they create are still cause for concern. “There seems to be very inconsistent terminology and presentation of MR safety-labeling information in contemporary product labels that today are elective for many manufacturers. If there's a greater movement toward requiring MR safety labeling, I worry that the FDA has both clear uniform standards for labeling consistency and the device reviewers who understand the peculiarities of MR safety enough to understand when to press manufacturers for more useful information on safe conditions for use.”
The FDA has issued a number of guidelines in MR safety over the last few years. In 2020, it warned patients to be aware of and remove face masks containing metal parts
before entering MR rooms, following an incident where a patient suffered burns during an exam that were consistent with the shape of a mask.
Another potential hazard is trendy magnetic eyelashes, which are prone to cause substantial artifacts and may detach during procedures
The report is available to view on the FDA website.