Ferromagnetic detection

QinetiQ scientists have developed a new ferromagnetic detection system that will protect MRI suites and provide a new level of safety for patients, medical staff and equipment.

The QinetiQ Ferroguard MRI System, as it is called, automatically scans people as they enter MRI suites and sounds an alarm if any potentially lethal ferromagnetic objects are detected.

Conventional archway metal detectors are large, cumbersome, difficult to install, restrict access and will alarm on all metal objects. But Qinetiq says that its Ferroguard MRI system is inexpensive and simply comprises a small box bolted to either side of a doorway or corridor. It allows harmless metals to pass by and only gives an alarm when ferromagnetic objects are detected.

MRI suites act like giant magnets and attract ferrous objects, which means that great care is required by both patients and hospital staff when they enter. Three years ago a child undergoing a MRI examination received a fatal head wound when the machine’s powerful magnet pulled a ferrous oxygen canister inside it. Other reported accidents where ferrous objects have been drawn into the machinery have involved a defibrillator, a wheelchair, a respirator, ankle weights, an IV pole, a tool box, a vacuum cleaner, mop buckets and even a pallet truck. MRI suite incidents occur in every 100 to 1000 scans – equivalent to each MRI facility having 17 incidents per year and one serious incident every three years.

Throughout the world there are around 15000 MRI units. 3000 new systems are sold each year and there is a five-year replacement schedule so the number of incidents is likely to rise. MRI accidents are proving costly to medical facilities. As well as injury and mortality to patients and employees, there is also the cost of litigation, repairs to MRI equipment and loss of imaging time.

QinetiQ in partnership with ETS Lindgren, which has a large proportion of the US market in MRI room installations, successfully sold its first ten units of QinetiQ’s Ferroguard MRI in North America in May this year.

The product was launched in Europe in June 2004 at the UK Radiological Congress in Manchester.

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