Radiology Today Interview: Tobias Gilk — Setting Up an MRI Safety Program (Part 2 of 2)
Vol. 15 No. 12 P. 28
Tobias Gilk is a noted expert in MRI safety, operations, best practices, and accreditation standards. He also serves as senior vice president of RADIOLOGY-Planning, which designs radiology, nuclear medicine, and radiation therapy facilities for health care providers. He was formerly the president and MRI safety director for Mednovus, which manufactures ferromagnetic detection products. He has served on the ACR's MR Safety Committee, and is one of the coauthors of the ACR Guidance Document for Safe MR Practices: 2007. He currently operates an MRI/radiology consultancy, Gilk Radiology Consultants. He has written or contributed to hundreds of articles, presentations, and best-practice standards documents on MRI safety. See November's edition for part 1 of this interview.
Radiology Today (RT): The first segment of this interview focused on the three biggest causes of patient injuries from MRI exams: burns, projectile injuries, and noise. Those areas cover a large majority of reported injuries. At the same time, looking at just some of the issues can't constitute a sound plan. What else should facilities be thinking about?
Tobias Gilk: Focusing on one or two items, to the exclusion of all else, doesn't truly create a safe environment. It is, however, important to identify the relative weighting for the different risks. If we look at the frequency of injuries reported, burns are at the top, projectile injuries are second, and hearing damage is third. But I do not propose that we ignore what comes in fourth, or later, on that list.
RT: So, in the bigger picture, where do you start?
Gilk: I recommend that the MR medical director, who is presumably a radiologist and responsible for MR practices and safety, start with two things. First, review policy and procedure manuals annually. In MR, we frequently update our technology, whether it's a new software package or a different coil configuration. We also fairly frequently update our clinical applications, whether it's adding MR-guided biopsies or stroke protocol. As the technology changes and the clinical utilization changes, our policies and procedures need to keep up. If your policy and procedure manual has a thin layer of dust on top of it, that probably means no one has opened it for a long time and the site is due for a review. What I recommend is to have the medical director review and endorse each policy and procedure specific to MR once a year. Done regularly, this process shouldn't take more than one hour, once a year. Simply go through each protocol and make sure they're all current. Make sure the protocols reflect the current imaging technology available to the provider and the current clinical utilization available to that provider.
It doesn't bother me to come in and see a policy and procedure manual that has several signed and dated signatures from the MR medical director each year because that policy or procedure hasn't changed over that period of time. Some things don't need to be updated every year. When I go through the manuals and see contemporary signatures, I feel confident that the MR medical director is actively engaged in safety for that site.
The second key thing I strongly recommend is that the MR medical director and his or her appointed MR safety officer identify training opportunities to expand their knowledge, particularly on the practical aspects of MR safety. There is a lot of academic information about MR safety that requires technologists and radiologists to interpret to put to effective use at their site. This step places an extra burden on radiologists and technologists. As administrators we need to do a better job of providing directly applicable, practical safety training to those people who are principally responsible for safety in the MR environment. So updating policies and procedures on a regular basis and seeking out relevant practical training for the MR medical director and the MR safety officer are two keys steps to an ongoing safety program.
RT: That information—specifically your current policies and procedures and what's going on in the MRI safety community—is then applied to the components of your facility's program.
Gilk: That's a good place to start. For providers who want to tackle this on their own, but again, do not want to bite off more than they can chew, I suggest a risk-weighted approach. Identify what for you, in your facility, is the single greatest risk. You might decide, "I can't simultaneously address burns, implant injuries, and everything within my organizational structure, so I'm going to take one of those areas and work on that. After tackling that area we'll take on the next."
RT: As mentioned earlier, the first installment of this interview addressed burns, projectile injuries, and noise damage. Please address some other concerns and best practices, such as implant issues and cryogen safety.
Gilk: I recently attended Dr. Emanuel Kanal's MR safety officer and medical director course. He posed a really interesting question to the more than 200 people in the audience. He asked, how many attendees were aware of a patient deliberately lying about having an implant or device in order to get an MRI scan? About 20% to 25% of the audience raised their hands. The notion that we ask patients these questions and we can't count on them to give us honest answers makes the hair on the backs of radiologists' and technologists' necks stand on end. There are enough problems with patients forgetting about things, simple omissions, but to have patients misrepresent risks to their providers is really worrisome.
There also is information circulating, based on small studies or limited safety criteria about implants, that has been translated into headlines proclaiming, "All Pacemakers Safe for MRI." These broad overgeneralizations do a horrible disservice to patients and providers alike by misconstruing the potential risks associated with MR imaging studies for patients with implanted devices. It's true that the vast majority of implants and devices are getting better in respect to MRI safety. The industry is making tremendous progress, not just in the MR-conditional labeled pacemakers that are getting a lot of attention, but across the board.
That said, there are significant risks associated with inappropriate MR imaging of implanted devices. It's still important to prospectively identify patients with implanted devices. Because of these risks, we spend a tremendous amount of time researching implanted devices. There are tools to help manage this, including websites that catalog and identify implants and devices. Many people are familiar with the website www.MRIsafety.com. There's also another resource that has, in my opinion, an even more robust search engine: MagResource. Either of these sites can be really helpful in identifying the specific criteria from manufacturers about what can and cannot safely be done with MRI imaging in relation to a certain device.
RT: While devices are improving in terms of MR safety, this issue is not going away is it?
Gilk: The bottom line is that as the population continues to age in the United States imaging facilities will see more patients with implants and devices. For the past six to eight years, about one in 10 Americans get an MRI exam in any given year. By automatically excluding patients with devices, we deny MRI scans to people because we feel as if they present an unaccountable risk. I think that we are starting to recognize that we're turning away too many patients for whom the implanted device risks are low if not nonexistent simply because there have not been effective criteria for providers to assess those risks.
Part of correcting this involves including cardiologists and others in the scanning process to help assess the risk involved with MRI imaging. That will be a piece of MRI safety for implanted devices going forward. Even without specific safety criteria from the manufacturer about a device, providers need to do a better job, in general, of being able do an analysis and make a determination about the risk of scanning. Health care providers make risk-weighted decisions all the time. In MR, we've become risk-averse to the point where we're denying scans to patients who could benefit clinically from them. I think it's time that we as an industry look at the way in which we define, assess, and mitigate risk because there are other solutions besides, "I'm sorry, we won't do your scan because you have an implanted device."
RT: What are some best practices for cryogen safety?
Gilk: Much of cryogen safety is determined at the time the facility is built out and the MRI system and cryogen vent pipe, or quench pipe, are placed and installed. First, facilities need to follow MRI system vendor criteria for designing and building the cryogen vent pipe.
Facilities should also include a means of pressure relief in the event of a cryogen leak into the MRI room. For example, I used to be one of the biggest proponents of MRI room doors that open out, with the idea that a pressure build-up inside the room would push the door open and help relieve the pressure. That recommendation was born out of MRI standard room door and RF shield technology in place about 10 years ago.
However, in the past 10 years there have been tremendous changes and advancement in RF [radio frequency] shield systems. One change is that door mechanisms do not operate in the same way they did 10 years ago. Many newer doors, whether they're the pneumatic air seal doors or latching kinds of configurations, their designs mean they will not budge if the room positively pressurizes. So, the outward-swinging door is no longer the pressure-relieving mechanism I'd hoped it would be. As a result, MR system manufacturers recommend some sort pressure release hatch within the MRI enclosure, so if the pressure builds up in the room, a panel in the ceiling, for example, would pop out and allow the pressure to escape the scanner room. Then the door will operate just fine once the pressure is relieved. A pressure relief mechanism separate from the main door in and out of the room is an essential safety element. It is more easily accomplished in the initial construction, when you're siting the magnet.
If your facility doesn't have such a separate pressure relief mechanism, the next time you ramp down the magnet to do other work, take that opportunity to install a pressure relief panel.
One ongoing opportunity to verify safety is an annual inspection of the cryogen vent pipe system and the cryogen vent path. If you have a wood-burning fireplace, most people know that you should have your chimney inspected on an annual basis. Well, the cryogen vent pipe is essentially the chimney for the MRI scanner. The inspection protects the device itself, but also the patients and staff that might be in that area during a quench.
Coordinate this inspection with your MRI system vendor because there are parts of the cryogen vent system that, quite frankly, you don't want your staff messing with. Utilize someone from the equipment vendor who is trained to check this equipment, particularly the pieces directly connected to the MRI scanner. Have the vendor's technician work in conjunction with someone from your facility. This inspection includes making sure that any exposed lengths of pipe inside the magnet room look to be in good condition, confirming that where two pieces of the quench pipe system connect, that connection is tight, as well as verifying that any insulation called for by the MRI system manufacturer is in place and that there is appropriate insulation over the pipe.
When the vent pipe reaches the RF shield ceiling, it is usually inaccessible from that point until it exits the building. So what you're left with is inspecting both ends—from the magnet to the RF shield ceiling and where it discharges to the outside. If you find something on either end that causes concern, then you take it to the next level and get somebody with a fiber optic camera to inspect the middle section of the quench pipe.
On the inside section, you want to check the insulation, the pipe diameter, and the stoutness of the connection. Outside, make sure there's appropriate signage identifying the risks associated with cryogen discharge from the pipe, that there's a minimum clear area marked around the quench discharge, and that there are no air intakes or air conditioning systems near the pipe. You don't want to suck that helium gas back into the building through the air conditioning system.
Also make sure that the cryogen vent pipe complies with the building code. There has been a change in many building codes in recent years regarding the vent pipes. Codes are increasingly prohibiting the quench pipe configuration that goes vertically up through the roof, makes a 90-degree turn, and discharges horizontally. The reason for that is that a wind-driven rain can essentially push rainwater, moisture, precipitation, and snow into the mouth of the quench pipe. The likely place for that moisture to go is down. Nine times out of 10, the bottom of down is on top of the pressure relief valve, the burst disc, or the MRI scanner. If water inside that part of the MRI quench pipe, right at the burst disc, freezes, that essentially negates the quench pipe and chimney. That means that, in the event of a quench, the cryogen has no place to go but into the scanner.
RT: When the discharge pipe comes up out through the roof, does it do a U-turn so that it's pointed down, or is there some other kind of cap?
Gilk: It could be a full U-turn in the pipe, but there are also details where the pipe coming straight up through the roof would have a fitting like a tin can larger than the diameter of the pipe over the top of the pipe. The gap between the cap and the pipe allows the gas to escape downward to the outside. But for moisture from the outside to get in, it would have to go up—and water doesn't like going up.
Any operators' manual I have ever read says the quench pipe should be inspected annually. The basic elements of the quench pipe inspection do not require an outside consultant. For the basics, it just requires an hour of opening up the ceiling tiles in the magnet room and coordinating a scheduled preventive maintenance visit from your system vendor.
After inspecting inside, go up on the roof where the discharge is located and check conditions there. If those inspections turn up something worrisome, you may need to bring outside experts in, but a quench pipe inspection is something every major MRI system provider should be able to provide, and should do on an annual basis.
RT: So how do you put it all together?
Gilk: First, your MR medical director and MR safety officer must be well educated about MRI safety practices. Then, the sooner you can look at all the risks in your facility the better off you are in protecting your patients and staff, as well as protecting your facility from liability that may be associated with a failure to properly care for those patients. Identifying risks and tackling them in discrete packages of risk allow you, over the course of six to eight months, to update your policies and procedures and will help you to do a much better job of handling those risks. It's not a single project; it's an ongoing process. ■