By virtue of the fact that hospitals, by definition, are meant to be filled with the sick, the frail, and the disabled, a fire in a hospital presents a more serious threat than to just about any other building type. It is for that reason that life safety measures are more strictly regulated, checked, and re-checked, in hospitals than in nearly any other type of building. The result is that fires in hospitals are rare… but yet they do occur.
And when a fire is near the MRI suite (even if you’re not in a hospital), there are particular concerns that need to addressed, such as evacuation, fire department coordination, and magnet quench protocols. In December there were two examples of MRI fires highlighting these issues that made the press.
Control room remnants: Royal Hampshire County Hospital
The first was a fire that broke out in an imaging addition to Royal Hampshire County Hospital, Southwest of London, England. That fire appeared to originate in the roof structure of the building, above the CT and MRI imaging suites. The imaging addition was successfully evacuated (including the patient who was having an MRI exam at the time) as were adjacent areas within the hospital, and nobody was injured.
Apparently the fire above the ceiling destroyed the cabling running to the MRI scanner, including the control circuits that connect the remote quench activation buttons to the scanner, itself. Even though they attempted to discharge the liquid cryogens from the scanner to remove the magnetic field by pressing the quench button, with the control circuits severed, there was no way to manually de-activate the magnet.
So the fire raged (at one point, drawing a hundred firefighters), but the active magnetic field of the MRI scanner within the building required firefighters and equipment to maintain a critical safe distance (a lesson learned purportedly after some equipment got pulled into the MRI). It was almost a certainty that either the heat of the fire, or the torrents of water poured on the building, would quench the magnet within. Remarkably, neither did. The building was largely collapsed, the fire extinguished, but like the proverbial Timex watch that ‘takes a licking and keeps on ticking’, the RHCH MRI scanner remained trapped in the rubble, at full field!
For those who have seen the force and volume of cryogen discharge in a quench situation, it is most definitely not an event you want to see ‘up close and personal’. Unfortunately, the solutions to initiate a quench for this magnet all required sending personnel into the most dangerous areas around the MRI scanner. For more than 10 days, the active magnetic field of the MRI prevented the fire investigation or cleanup.
In response to this accident, the UK’s MHRA has reaffirmed a requirement that any and all safety circuits must be protected with not less than a one-hour fire rating.
Outside St. Luke's Hospital - Riverside, during firefighter response
to MRI fire.
The other recent MRI fire occurred at St. Luke’s Hospital – Riverside, in Bethlehem Township, Pennsylvania. In this event, a patient was in the midst of being scanned (on a very new MRI scanner) and complained that she was getting very hot. It was reported that the composite material cowling of the MRI scanner was actually glowing orange from the heat on the other side! The patient was evacuated, and very shortly thereafter, these plastic covers ignited into flames!
It was reported that the fire was extinguished by MRI department staff, using an appropriate ‘MR Conditional’ portable extinguisher, before the municipal fire department arrived on site.
In this case, the magnet was successfully quenched, power killed to all of the subsystems even before the fire department arrived in force. The facility was checked, and no evidence of fire was found anywhere else in the building.
In this particular case, informed sources have indicated that the source of the fire was electrical arcing at an improperly anchored gradient coil power cable located under the plastic cowlings covering the MRI scanner. In lieu of removing and replacing the scanner, the hospital and the MRI system manufacturer agreed to repair the MRI in situ in the hospital, which was thought to be a quicker resolution. We don’t currently have any information as to whether the refurbished MRI scanner has been returned to duty.
Though the origins of these two fire incidents are radically different, they each point out the importance of preparations to protect people, facilities and equipment. While the planning for an MRI service should involve conversations of greater detail, here is a bulleted list of several considerations…
Has the facility been designed and built with appropriate fire-resistant construction?
Does the MRI suite have the appropriate type of fire-suppression system?
Is the suite provided with at least one MR Conditional portable fire extinguisher?
Is the building’s emergency exit and emergency lighting effective?
Has the staff been appropriately trained to use portable fire extinguishers?
Are there fire-emergency policies and procedures specific to MRI?
Has the organization coordinated with local fire officials regarding the safety risks around MRI scanners?
In each of these two events, the fires were contained within the imaging suites, but in both of them, sections of each of the hospitals were evacuated as a precaution. Due to the risks and complications of fighting fires in and around MRI suites, it is essential that facilities, staff, equipment and procedures be prepared well in advance.