Peruse the list of medical professionals who make up the American College of Radiology’s blue ribbon panel on MR safety, and you might find yourself wondering how all of these people -- with their disparate interests and specialties -- got it together to create a single, defining document. The 15-person committee includes experts in MR imaging, patient safety, pediatrics, anesthesiology, imaging research, physics, MR technology, MR nursing, electronics, private practice, organized radiology, the federal government and, of course, the ubiquitous legal representatives.
But get it together they did, and the result is the "ACR White Paper on MR Safety" published in last month's American Journal Roentgenology. Dr. Emanuel Kanal, the director of Magnetic Resonance Services at the University of Pittsburgh Medical Center, chaired the panel.
"The key to forming the panel was to get representation across the board; to make sure that the panel was not controlled by one or two people," Kanal explained. "This ACR MR safe practice guidelines document represents the largest, most up-to-date, most inclusive and comprehensive attempt by any society or organization ever to provide consensus in a peer reviewed manner as to what is considered reasonable safe practice in MR environments."
The crux of the guidelines is the separation of the MR area in four separate zones: zone I refers to all public areas; zone II encompasses reception and the patient dressing area; zone III includes the computer and control room; and zone IV, where the scanner is located and is restricted to imaging staff (AJR, June 2002 Vol.178:6, pp. 1335-1347).
In an interview with AuntMinnie.com, Kanal discussed in greater detail the issue of zoning and other elements of the guidelines, answering some of the common questions that arise when facilities look into implementation.
What are your general recommendations for a facility looking to incorporate these guidelines?
It seems to me that for most sites, the implementation of these guidelines will be focused on two areas: Site access restriction and MR safety education. There are certainly many other points, including screening methodologies, but I think that if sites adequately focus on these two areas, it can have a tremendous impact on decreasing the incidence of adverse events that have occurred in MR sites to date.
Let’s imagine for a moment that we had an x-ray room that opens to the general access corridor. We are all familiar with having a light that says, "x-ray is on." We are all familiar with the fact that x-rays cannot be used for medical or diagnostic purposes until someone has demonstrated that they are certified, that they have had training in the safety aspects of x-ray. Why all the concern about an x-ray? The concern is that radiation can be harmful (and) that is not intuitive: You can’t see it, you can’t hear it or touch it or feel it or sense it in anyway.
It’s sometimes hard to understand that the same applies to magnetic fields. They can be harmful. It’s not intuitive. You can’t feel it, see it, taste it, or touch it. There’s no way you can be aware of its presence until, perhaps, it’s too late. Plus, the harmful effects are much more immediate and can be more definite than the vague effects of perhaps inducing a mutation years down the line. Yet these MR-site related magnetic fields are essentially not regulated or controlled.
You mentioned safety education. How does your institution handle MR personnel education?
I recently created some MR safety videotapes and DVDs. There are two of them: One of them is 60 minutes in length and the other one is a 90-minute presentation.
The 60-minute presentation is designed for level 1 MR personnel as described in the guidelines. It’s targeted to an audience such as security, maintenance, housekeeping, and respiratory therapy. It also includes firefighters and police officers. These are the people who might occasionally find themselves in the MR environment.
The 90-minute presentation is geared toward level 2 personnel, such as the MR technologist, MR physician/radiologist, etc. This covers additional topics besides static magnetic fields and quenches, such as safety issues associated with radiofrequency (RF) burns, gradient switching safety issues such as induced voltages, auditory noises, and hearing concerns.
What would be an example of a "worst case scenario" involving an MR suite set-up? How would you suggest fixing it?
An MR scanner with a scan room that opens to a public corridor. That definitely exists in many sites today. I would think that’s an example of worst case scenario. If that’s the case, what would be required would be to find some way to physically restrict access to that room. And how does one do that? It might require putting up a doorway. It might require putting up a lock or a door that doesn’t open except with a pass key. I personally don’t prefer combination locks; combinations tend to be passed around.
At the University of Pittsburgh Medical Center, we have our cards or IDs that, if you swipe the ID card itself through the reader, it reads the information and checks if you are cleared and opens the door for you.
This is an ID card that you need throughout the hospital anyway. This is just one more area that it does -- or doesn’t -- clear you into. How hard is it to put up? It’s not free. But daunting? No. Only for someone who does not find himself motivated to try to implement a safety restriction on access to magnetic fields. It’s a matter of implementing what prospective sites can do from the beginning, which is to ensure that people don’t accidentally walk into MR scan room environments that might be harmful to them.
I am aware of certain circumstances where -- because of the architecture or because of the way the room was positioned or because of the way the building happens to be designed -- not only does the room open to a general access corridor, but the front door to the room is not readily accessible to the technologists in the MR control room.
The technologists and those that are responsible for ensuring the safety of the examination are not physically in sight of the front door to the magnet room, to zone IV. It is for sites such as these that the guidelines are most necessary, for the protection of the patients and healthcare practitioners at these sites.
How would you suggest that facility manager assess the current setup? In an effort to meet the safety guidelines, could a complete overhaul of an MR site be a possibility?
I can’t picture how that would be the case. (For assessment), they should make believe that they are an uninitiated layperson, and that they are standing anywhere in their site. They should assess their site to review and ensure if they would be standing anywhere publicly reachable, that they do not find themselves in a position where they could accidentally (be) exposed to magnetic fields.
In most circumstances, where reconfiguration is necessary to meet these guidelines, (it) would require nothing more extensive than putting up an extra door or wall where one may not presently exist.
Could you elaborate on the guideline’s suggestion of double screening for non-emergent patients? Why did the committee feel that this was important given the time it could potentially add to an exam?
(We had) virtually unanimous feedback from the technologists that patients will tell someone something that they did not tell the other person. How many times has it happened at my site that we were on our way into the room and I said "One more time, you don’t have any implants, do you?" (The patient replies): "Well, I do have this hearing aid."
The second screen finds something that the first one doesn’t. Some have said, "Well if you would do the first screen correctly..." This kind of statement can only come from one who has no familiarity or experience with the day-to-day running of real MR scanners in pressing clinical situations. It has nothing to do with how you’ve done the screen. It’s human nature.
As a result, we said that, if it’s non-emergent, patient screening should be performed by two people. Only one of them has to be level 2 personnel, meaning a technologist or a physician. The first (screening) could be the receptionist asking the patient to complete the form and subsequently going over the questions with them.
It falls back to the same point as x-rays. Although people today know that x-rays are harmful, it’s hard to think of them that way because you don’t see them. It’s the same with magnetic fields. We’re simply not used to dealing with them.
Everyone knows that if you are pregnant, you inform a technologist before undergoing an x-ray examination. We don’t have that kind of sensitization to MR safety concerns in our industry -- yet.
Any reason why the guidelines don’t address open MR scanners or low-field MR systems?
There is a tremendous misconception that the safety issues of open MR should be different from closed MR. A magnetic field that can potentially cause trauma is a magnetic field that can potentially cause trauma.
People say, "This is a low or an ultra-low field system. It’s only 3,000 gauss." But think about what 3,000 gauss is. The magnetic field that’s keeping your refrigerator door closed is about 200-250 gauss. And this is 3,000.
The words open and closed MR are, in my opinion, marketing terms. From a safety point of view, they also have a magnetic field gradient; they also have a spatial gradient; they also have magnetic fields that, from a day-to-day basis, are powerful.
