When a young girl was injured during an MR exam earlier this year, Tobias Gilk, a member of the American Board of MR Safety, told reporters that more than 7,000 MR accidents take place in the U.S. every year, an increase of 500 percent since 2000. While those accidents represent a miniscule fraction of the estimated 30 million MR exams performed every year, they are still unacceptable — and there is plenty being done to change the tide. One aspect of an MR exam that makes it desirable is that it requires no radiation dose to the patient. Yet for something so safe, there is still plenty of danger to be mindful of when working with and around these enormously powerful magnets. The topic must be approached from a variety of perspectives, some clinical, others operational and physical.

Contrast agents and the radiologist-physician relationship
An estimated 30 percent of MR exams depend on the use of gadolinium-based contrast agents (GBCAs) to make the image easier to interpret, but recent publications have reported that deposits of GBCAs remain in the brains of some patients who undergo four or more contrast MR scans.
While the clinical implications of this are still unknown, it could have an impact on the degree of involvement radiologists have in choosing patient exams — which is currently suppressed by legislation designed to limit physician self-referral.

The Stark amendments and anti-kickback laws prohibit a physician from ordering an exam and billing CMS for it. Those regulations are designed to keep doctors honest, but it also means that decisions are made by referring physicians who may not be aware of all the finer points of the medical imaging exam being performed.

For Dr. Emanuel Kanal, director of MR services and professor of radiology and neuroradiology at the University of Pittsburgh Medical Center, the new findings illustrate a limitation to the otherwise useful legislation. “An order will simply state ‘MRI with contrast,’ but what dose? What rate? What route?” asks Kanal. The evidence increasingly suggests that these are important safety considerations that should be personalized to an individual patient’s needs.

Preventing errors while forgiving them
Making sure nobody gets close to the machine with items that will be magnetically drawn to it is at the core of MR safety. “We will literally tackle you at the door if you try to go in without following the proper protocols,” says Patricia Robberstad, MRI manager at Mount Sinai Roosevelt. “People don’t understand that a magnet is a magnet all the time — there’s no on and off switch — if you put a magnet on your refrigerator it doesn’t fall off at night when you turn the lights off.”

There have been reports of all kinds of heavy metal objects getting pulled into an MR, such as oxygen tanks and floor buffers. Those situations can be fatal for someone sandwiched in that gravitational pull, and even if there are no causalities, the repair process can be costly and trigger prolonged downtimes.

The FDA established the Manufacturer and User Facility Device Experience (MAUDE) database to keep track of these kinds of accidents, but according to Kanal, many of these incidents never make it to that database. Part of the problem, he says, is the way facilities discourage openly discussing adverse events.

“The No. 1 instruction if anything comes close to happening is always the same: Keep your mouth shut,” he says, adding that this kind of culture hampers the ability to learn from errors and reduce them in the future. Kanal believes hospitals can take a tip from pilots, who utilize the Air Force Aviation Safety Action Program (ASAP) to report accidents and incidents in an identity-protected, Web-based model without penalty. If the error was neither criminal nor intentional, their record becomes clean again after six months. In this way, a better record is kept of mistake patterns and improvements can be made.

Vigilant screening and the four zones
At Mount Sinai Roosevelt, Robberstad and her colleagues utilize the American College of Radiology’s four zones of MRI safety. She says the first zone is for the general public and might be accessed by just about anyone, including doctors dropping off paperwork or someone coming to schedule an appointment. The second zone is limited to patients who have satisfied a written screening form.

Robberstad and her colleagues are making sure people remove things like hair clips and watches, but they are also screening for pacemakers, implanted devices and medicine patches. “People need to understand they can’t just walk in there. You have to play by the rules in order to keep everybody safe,” she says.

The third zone is for patients and staff members who have completed the written screening and also answered verbal questions to ensure they don’t have anything on them that would make proximity to the MR potentially hazardous. According to Robberstad, it’s common for a visitor to check a box saying they do not have something on their body, but then when asked verbally, they remember that they do.

The fourth and final zone is the exam room itself, with entry requiring passing through ferromagnetic detectors. “There have been times when patients go in with a paperclip in their sweatpants pocket which could get lodged in the scanner, but a situation like that does not necessarily cause harm,” says Robberstad.

Another time a patient had a staple stuck in the tag on the back of their shirt from the drycleaner, which showed up as an artifact in the image, but didn’t cause any adverse effects. These kinds of harmless incidents are far more common than adverse events, but the key to eliminating all of them entirely is in education, according to Robberstad, and she says vigilance is key.



Ferromagnetic detectors
Ferromagnetic detectors are similar to the metal detectors found in traditional security settings, but will only signal magnetic material. For MR safety, these detectors can be vitally important. Mark Keene, CTO of Metrasens, is credited with developing these detectors, and credits his invention to a tragedy.

“Six-year-old Michael Colombini died in July of 2001 because someone took a sealed oxygen cylinder into a magnet room and he was in the scanner at the time and the cylinder struck his head, and he died from massive hemorrhaging,” recounts Keene, a citizen of the UK who happened to be in the U.S. at that time. The tragedy resulted in rapid innovations by Keene, who called on his military research background in submarine and land mine detection to create the first ferromagnetic detector prototype in November of the same year.

MR-safe metal equipment is always being developed, and includes aluminum IV poles, specially designed gurneys and certain patient monitoring equipment. Distinguishing these items from MR hazardous items is not always easy with the naked eye. Keene recalls a few months ago when a young child with a programmable shunt valve in their head was being admitted for an MR. The technician doing the screening stopped the procedure because — for reasons unknown at the time — the detector was going off. Afterward, when the presence of the shunt valve came mto light, the team realized a potentially life-jeopardizing event had been prevented.

Metrasens, and other companies, are working to improve their detection abilities while also cutting down on troublesome false positives — which can cause alarm fatigue and lead to carelessness. “There’s a temptation to make the equipment more elaborate and more complicated, but we don’t really want to go that way because there is so much complicated equipment in the MR environment already, so, in a sense, it’s about making it simpler and easier and more intuitive to deal with,” says Keene.

Certifying MR ‘pilots’
For Kanal, MR professionals can learn a lot from airline safety. “The No. 1 cause of adverse aviation events is pilot error, and the one thing we don’t certify in MR is the pilot,” he says. There are software certifications, and hardware certifications, and the ACR has an MR accreditation program that ensures the safety and upkeep of an imaging facility — but there is no standard accreditation to distinguish the best people for conducting the exams. Kanal helped form the American Board of Magnetic Resonance Safety (AMBRS) last year to help meet that need.

“It exists for one reason only: The certification of the people who are charged with overseeing safety in the MR environment, whether clinical, or research.” The board is composed of international voting and non-voting members representing MR safety from all walks of the profession, including technologists, physicians, industry and regulatory. By establishing the roles of MR medical director, MR safety officer and MR safety expert, Kanal and his colleagues hope to eliminate a lack of accountability in the MR environment.

There are 100 questions, including true-false and multiple choice, testing basic MR safety information awareness as well as the ability to apply that information in real-life scenarios. If someone passes the test they achieve MR accreditation which lasts for a decade. After that, recertification is necessary.

Dressing for the occasion
In days gone by it was not uncommon for patients undergoing MR to wear regular clothes inside the magnet, but as more clothing is being produced with silver and copper impregnated into the fabric to be antibacterial, that’s changing. Kanal says that because they can be electrically conducted, those garments can cause burns and, consequently, gowning patients is almost mandatory. At Mount Sinai Roosevelt, Robberstad says all of her patients wear hospital gowns before undergoing MR.