Mark Keene is a specialist in high sensitivity magnetic sensors and systems, and for the past five years, his expertise has been available to the imaging community through Metrasens Ltd, a company that manufactures MRI safety systems.

Last month, Keene, the chief technology officer with Metrasens, spoke with DOTmed News from a hotel room in Sacramento, Calif., after a flight from the United Kingdom. (He’s the main supplier of magnetic and sensor detection apparatus expertise for the UK’s Ministry of Defense.)

Keene talked about his invention, the FerroGuard System, and the issue of MRI safety in the U.S. and abroad.
DOTmed News: How common are patient or staff injuries as a result of ferromagnetic objects entering the MRI room?

Keene: Thankfully, fatal incidents are comparatively rare. There have been about two in the last eight to nine years or so that I’m aware of. But with injuries, there’s a lot more than that. The truth is we don’t actually know how many accidents there are because we feel that about 90 percent of those accidents go unreported. This is because it’s quite embarrassing for a hospital to have an accident.

When we go around and talk to hospitals, we often come across ones that have had a major incident like a gas cylinder, a gurney or a chair go into the magnet and the majority of MRI magnets we’ve seen have had some minor incidents, like a pair of scissors, paper clips or very small objects get pulled into the magnet. These very small incidents are incredibly common and they can injure people. Fundamentally we don’t know [the rate of minor incidents] because there isn’t a requirement for hospitals to report these accidents.

DOTmed News: Metransens offers the FerroGuard MRI system, a visual and audible alarm that alerts staff before ferromagnetic material makes it into the MR room. How did you come up with the idea for FerroGuard?

Keene: Throughout my research career, I worked in a big research and development company for the government on submarine and land mine detection. I developed sensor technologies to detect these things.

I was at a conference once in the United States on these subjects and I got back to my hotel in the evening and slopped down in a chair and just put on the TV. At that point in time, a news story was on about a small boy in New York, Michael Colombini, who had died that day. While he was in an MRI machine, somebody took an oxygen cylinder into the room. It got pulled out of the technician’s hands and accelerated into the magnet, striking the boy in the head. He died of massive hemorrhaging. Because of my background in submarine detection, I immediately knew how one could develop a piece of technology that would prevent that accident from happening and that would give a person a warning if they were going into the MRI room with something that is likely to get pulled in.

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