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As mentioned earlier, I had a MRI today... I wasn't in the waiting room for long so I didn't have a chance to read the bright yellow folder labeled "Earthquake Guide during a MRI."

But as I walked home, I kept thinking about that folder because it seemed so bizarre to me. Was this a thing that happens a lot that necessitated a guidebook?

I had never considered what would happen if you were in the MRI during an earthquake? Was there actually an official safety protocol for this? Except... try to wriggle your way out and go somewhere safe?

3

Do nothing, stay inside the MRI machine.

I never performed MRI scan in the past but I had experience of several quite big earthquakes within the last 10 years. So I provide my thought on this for your reference.

I have to say that you probably already in the safest place during an earth quake in a building for two reasons:

1) rooms for big scanners are usually build with solid concrete and very likely to be strengthened further comparing with standard concrete building for accomodation or office. That makes the room very unlikely to collapse during an earth quake.

2) MRI machine is basically a giant piece of metal. If earth quake strikes during your scan, you have already surrounded and protected by this heavy and strong metal structure. This makes your situation even safer as you will be well protected even the building collapse.

Based on my personal experience on earth quakes, I think you will be pretty safe even there is a magnitude 8 or less earth quake happen during your MRI scan. For the quakes that more than magnitude 8, shallow and close by, well, good luck.

3

You most definitely do not want to be in an MRI machine during an earthquake. The superconducting magnets in an MRI scanner are cooled by liquid helium. If the cooling system is damaged and there is a leak, this could be very bad for you.

I have not seen what is in the yellow folder, but earthquakes present a particularly dangerous situation for MRI machines that is not common with fires. As you may know, you cannot bring metal into the scanning room. This means you need a to use a special wheelchair or stretcher to remove someone who is not able to move on their own. During an emergency a staff member would normally quench the magnet by venting the liquid helium to rapidly eliminate the magnetic field and allow emergency personal to enter the room with standard equipment. Quenching the magnet can break the machine so you would only want to do it when necessary. The quenching system is generally designed to handle fires, but can be damaged during an earthquake (https://www.imedco.net/changing-seismic-regulations-and-the-effect-on-mri-shielding-design/) which could allow the liquid helium to enter the scanning room. The quenching process is pretty dramatic

My guess is that the big yellow folder provides guidance on removing patients from the scanning room, when to quench the magnet, and what to do if the emergency quench button fails.

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    most patients won't require any sort of stretcher or wheelchair to get them in and out because they're ambulatory. If one was required it would probably be parked outside the room having been used to deliver the patient. – Kate Gregory Sep 4 '19 at 16:32
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    This is probably the correct answer, but it lacks supporting sources to back it up. For example, you say if the cooling system is damaged it could be very bad for the patient. Having seen a video of a quenching I can believe that, but adding a source to back it up would improve your answer. – Carey Gregory Sep 4 '19 at 22:08
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    @CareyGregory I don't think common knowledge statements (like liquid helium being dangerous) need references. The answer gives the key termsND some links to look up more information. – StrongBad Sep 4 '19 at 23:17
  • @KateGregory I didn't mean to imply that everyone needed a wheelchair. I just wanted to point out that someone responding to an emergency may not know that you cannot bring metal into the scanning room. – StrongBad Sep 4 '19 at 23:37
  • @StrongBad It's not about what you consider common knowledge. It's about writing a good answer. I was just trying to help. – Carey Gregory Sep 5 '19 at 4:11
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Via the UCLA Brain Mapping Center, in the event of (emphasis and formatting added):

Non-Fire Facility Emergencies

  • Unscheduled Power Shutdowns
  • Earthquakes
  • Magnet Quench (catastrophic boil-off of helium)
  • Water Leaks
  • Foreign Metal Objects in the Magnet

Instructions are:

  1. Perform a routine electrical shutdown, or if circumstances such as a rapid flooding threaten to reach the equipment before a routine shutdown could be completed, perform an emergency electrical shutdown. Both shutdown procedures are described in the shutdown sections of this manual.
  2. Remove the subject from the scanner.
  3. If appropriate, evacuate the building and do not return until advised that it is safe to do so.
  4. Notify an ALBMC staff member of the emergency

Therefore, at least for that institution, it does not seem like standard earthquake procedure to perform a non-routine shutdown. Instead, start a routine shutdown and remove the subject. I don't see any recommendation to quench, even the "emergency electrical shutdown" is not a quench.

Different institutions may have different procedures, of course. However, quenching the magnet simply in the event of an earthquake does not seem prudent to me unless other circumstances occur:

Users of the ALBMC facility should only quench the magnet in the event that the magnetic field itself poses an immediate risk to life or major property. Two such circumstances are:

  1. A metal object is lodged in the scanner in a way that poses an immediate serious threat to a person (e.g., the person is pinned to the magnet by a metal object that is causing internal injuries).

  2. Fire personnel determine that there is no other alternative to entering the room with axes or other heavy gear when fighting a fire. If the absence of a major emergency, facility users should never quench the magnet by themselves, even if they are convinced that amagnet quench will ultimately be necessary

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