Many facilities planning for ferromagnetic detectors, particularly existing MRI providers who must retrofit the new technology into tight-fit suite layouts, have a hard time finding optimal locations for the new MRI pre-screening instruments.
Real estate within the outer walls of the hospital is at such a premium that a good proportion of MRI providers are already working within MRI suites into which their large (and frequently growing) operational requirements have been shoehorned-in. They could really do with several hundred additional square feet, so the addition of anything to the suite can trigger a domino series of complications.
Pass-through ferromagnetic detection portals, such as the Mednovus Sentinel® series products, can be sited as either free-standing or doorway-mounted instruments. One caveat for doorway-mounted versions is that the door should not swing through the aperture of the portal (door hardware, even on most RF-shielded doors for MRI suites, has ferromagnetic components and would set off the detector). This means that there is one side of the doorway that is ill-suited to receive a mounted portal.
For MRI suites where space is already at a premium, it is sometimes felt that mounting a ferromagnetic detector at the door into the magnet room is the only place where both existing operations and available space will permit.
But if the door to that room swings out (as is currently recommended by the majority of MRI equipment manufacturers), can you put the detector on the other side of the doorway; on the inside of the MRI scanner room? Physically, yes, you can put the instrument there. Physically, you could also use your MRI scanner room as a waiting area for patients with unknown medical implants and devices, but both ideas would have grave dangers.
The intention of ferromagnetic detection is to alert you to the presence of magnetically attracted materials before they get close to the magnet. Placing a ferromagnetic detector inside the room would only be less effective if were mounted at the face of the bore of the magnet.
Since it often takes a moment to react to the alarm of a ferromagnetic detector, the step or two that a person may take past the ferromagnetic detector isn’t typically a problem outside the MRI scanner room, but in the room where inches can make enormous differences in the magnetically attractive effects, those couple steps can make the difference between avoiding an accident or cleaning-up after one.
Couple the compromised effectiveness with the fact that – at one time or another – everything needs servicing, and you’ve introduced another object into the MRI scanner room that may necessitate servicing from workers with tools. The attempt at increasing safety has actually introduced a new opportunity for accidents.
Lastly, MRI equipment manufactures are (justifiably) nervous about the introduction of equipment into the room which supports the MRI scanner. Does this other equipment emit RF noise that might interfere with the MRI images? Is it going to compromise the function of the scanner? Will the magnetic fields of the scanner adversely effect the other equipment?
In response to these concerns, MRI equipment vendors typically prohibit equipment or devices that haven’t been tested and deemed non-disruptive. Even just placing a ferromagnetic detector inside the MRI scanner room would very likely void significant portions of your MRI manufacturer’s warranty.
The fact is that there are often alternate locations for siting of a pass-through ferromagnetic detectors. It may take a little creative thought or a willingness to slightly modify operational protocols, but typically there are a handful of possibilities for each site. There is no reason – whatsoever – to place a ferromagnetic detector inside the MRI scanning room, and it is extremely ill-advised to do so.Tobias Gilk, President & MRI Safety Director Mednovus, Inc. Tobias.Gilk@Mednovus.com www.MEDNOVUS.com