MRI Safety Concerns Prompt FDA Meeting

In recent years, speculations about imaging safety have swirled around the long-term effects of CT scans. But, industry leaders are hoping to now turn the water cooler conversation toward making MRI safer for both you and your patients.

Even though MRI scans themselves are widely considered to be extremely safe, data from the FDA Manufacturer and User Facility Device Experience database reveal patients and providers are sustaining injuries during the MRI process. In fact, from 2004 to 2009, the number of injuries spiked four-fold to 193 accidents.

Whether more accidents are really occurring or injury reporting is on the rise is up for debate among radiologists. But the trend is concerning enough to prompt the FDA to hold a conference later this month to examine the biggest MRI safety concerns and discuss best practices to truncate the number of incidents.

“There are increasing numbers of MR scans and an increasing demand to scan patients with implants or accessory medical devices and other equipment. With the increased use, we are also seeing a number of preventable incidents,” said Sunder Rajan, PhD, of the FDA’s Center for Devices and Radiological Health Division of Physics Biophysics Laboratory. “Given the new experience base, this is a good time for FDA to learn what MR practices are being used and what changes practitioners feel would improve safety to the MR environment.”

The Main Concerns

MRI accidents and injuries fall into three main categories: thermal burns, projectiles, and hearing loss in poorly protected patients.

According to Tobias Gilk, president and MRI safety director at Mednovus and senior vice president at the design and architecture firm Rad-Planning, thermal burns pose the greatest risk to patients because they are associated with a relatively recent technology advancement – gradient improvements that allow for better image quality and scan efficiency.

“Burns are a newer safety issue that have grown out of the advancement of stronger, faster gradients,” Gilk said. “Moving to a stronger magnetic field from 1.5T to 3T makes it necessary to use more radiofrequency, increasing the chance that a patient will be burned.”

In addition, ferromagnetic objects in the MRI suite also pose a real danger to patients and providers. The 2001 Colombini case in which a 6-year-old boy died when an oxygen tank flew across the room and struck him during his imaging procedure brought this risk possibility industry-wide attention.

Although these incidents are rare, they are expensive. A U.S. Department of Veterans Affairs’ Center for Patient Safety study found that each occurrence costs more than $43,000, accounting for MRI machine repair, injury treatment, and legal costs. It doesn’t, however, take into account lost revenue due to an inoperable MRI machine.

Regardless of the reason, Emanuel Kanal, MD, director of magnetic resonance services at the University of Pittsburgh Medical Center and chair of the American College of Radiology (ACR) MR Safety Committee, said you must still take precautions to prevent projectile accidents.

“The most serious incidents, albeit quite rare, involve projectile effects,” he said. “These need to be addressed if we are to significantly lower the incidence of MR-safety relative adverse events.”
Unfortunately, there are no regulations that require proper identification of materials unsuitable for being in a MRI suite, Gilk said. And, sometimes it’s the MRI suite itself that creates the risk. When it comes designing a new suite, he said, many office architects look at a prototype design and implement it without taking the unique factors of the hospital or physician office into account.

Implantable Devices

According to Terry O. Woods, PhD, of the FDA’s Devices and Radiological Health Division of Solid and Fluid Mechanics, the increase in implantable devices has opened up a new set of safety concerns.

“There is a new set of safety concerns arising from the clinical need to scan subjects with some types of implants,” he said. “Many implants can interact with the magnetic and radiofrequency fields present in the MRI scanners.”

The increased need for clear labeling is particularly important with these devices, said Bill Faulkner, MRI technologist, CT/MRI educator, and consultant. Some are labeled MRI safe, some MRI unsafe, and some MRI conditional. The conditional devices are tricky, he said.

“Any implantable device must be tested to determine if it’s safe for MR. We know anything metal is not MR safe,” Faulkner said. “However, with conditional devices, it is incumbent upon the MRI user to find out what ‘conditional’ means for each device. We can’t abdicate that responsibility.”
That means determining the proper field strength and the right radiofrequency.
Fixing the Problems

While MRI activities pose several safety concerns and place a lot of individual responsibility on providers and staff, many industry leaders agree on one strategy to solve these problems: education.

“There is a need for more education and seasoned knowledge about MRI both for the technologist and the radiologist,” Faulkner said. “I think a lot of assumptions are made that you can implement blanket strategies with MRI, but it’s not advisable.”

Faulkner recommended following the ACR MR Safe Practice Guidelines. First published in 2001, the white paper offers suggestions, practices, and guidelines to make the imaging technology safer for patients. Despite their usefulness, however, they have never been widely implemented, and the document is currently in its third revision.

Is It Time For Regulation?

Industry leaders agree that you should have regular standards that provide for MRI safety. However, feelings around federal or state intervention are mixed.

“I’d love to see national guidelines, but I don’t know whether it needs to be federal regulation. Unequivocally, I’d like to see a set of objective standards applied to all MRI providers to ensure they offer a basic level of expertise and safety precautions in the MRI environment,” Gilk said. “Whether it’s federal regulation or an agreement between state licensing or accrediting agencies could help us take the needed steps toward preventing accidents.”
Kanal agreed that regulation is needed, but he said it needs to come from within the radiology community.

“I do not, at this time, believe that external regulation is needed, with one caveat. MR sites must accept standardization of MR safety practices upon themselves in order to coherently and consistently prevent MR safety-related incidents and injuries,” he said. “We can either accept standards that we create and define, or we can wait for another terrible safety even to occur and be widely publicized throughout the world before pressure mounts on organized radiology to impose externally defined standards, guidelines, and practices upon us.”