External fixation and braces are typically very carefully screened for contraindication for MRI examination, but what may not be as frequently screened is the clothing underneath. We’ve received a report of a patient who received a burn from the specialty T-shirt, worn under their brace! The T-shirt, which included electrically-conductive silver fibers, purportedly acted as an RF antennae and produced focal heating.

This incident, like so many others, goes to show how so many risks in the MRI environment, such as concealed ferromagnetic threats, can be difficult to find if you don’t have the proper tools and knowledge with which to look for them.

Every MRI provider should avail themselves of the latest MRI safety information, standards, recommendations and peer accounts of accidents and near-misses in order to deploy the greatest protections, both for their patients and for their own risk management. For burn risks, this means diligent screening of everything that accompanies the patient into the bore. For ferromagnetic (projectile) risks, this includes the use of ferromagnetic detection systems.

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No, that’s not what the FDA just said, but the news in the FDA’s most recent alert is almost as dated as my hyperbolic example. What the FDA did in their March 5th alert on the MRI safety of transdermal medication patches was essentially recapture what had been stated in the 2007 ACR Guidance Document, which was very similar to what the ACR said in the 2004 edition of the White Paper on MR Safety, which was expanded from what was said in the 2002 White Paper.

But what the FDA wrote, and what their representatives said, were contradictory (not a first for the FDA). The carefully considered release states that some transdermal patches may contain concealed metal foils that would be subject to heating under certain MR conditions and that patients should consult with their physicians and the MRI provider about the appropriate course of action (the removal of some drug-delivery patches may alter therapies – and replacements, particularly for pain medications – can be extraordinarily difficult to get).

However, in an interview with the Wall Street Journal, Sandra Kweder, Deputy Director of the FDA’s Office of  New Drugs, was quoted as saying that if there was any doubt, patches should be removed. In fact, Ms. Kweder aluded to a pending requirement for manufacturers of foil-backed transdermal patches to place “remove before MRI” directly on the patch.

Fortunately, it seems that the medication side of the FDA and the device side of the FDA are combining their respective knowledge domains and that, if these patches are to be marked, it may be with the FDA / ASTM approved ‘MR-Conditional’ designation.

While it would be great to have a ‘one-size-fits-all’ response to the risk of medication patches in MR, I’ve yet to find a ‘one-size-fits-all’ response for any aspect of MR safety. The ACR Guidance Document and the printed FDA release got it right… make sure Technologists are aware of patches (where and what type they are) that an informed decision can be made as to the best way to minimize all risks to the patient (including the risk of an altered medication therapy).

So while the latest FDA information hardly classifies as ‘breaking news,’ it certainly doesn’t hurt us to be reminded of the multivalent hazards that are present in MR.