Coming soon to an MRI near you: Guns don't kill people.. MRI's kill people

[Brainonska511]

If the bullet went through him and pierced the dewar with liquid helium it couldve quenched the magnet with a person inside....the gunshot would be the least of your worries then.

The guy that originally set up the NMR spectrometer in my grad lab was like "I need this space clear, because if it quenches while charging, we'll have like 4 seconds to get out of the room".

 

[hal2kilo]

The guy that originally set up the NMR spectrometer in my grad lab was like "I need this space clear, because if it quenches while charging, we'll have like 4 seconds to get out of the room".

I'm familiar with the term as it relates to rapidly cooling metal, so I have the need to understand everything, so here's a thing about MRI quenching.

What Is an MRI Quench? (blockimaging.com)

 

[Brainonska511]

I'm familiar with the term as it relates to rapidly cooling metal, so I have the need to understand everything, so here's a thing about MRI quenching.

What Is an MRI Quench? (blockimaging.com)

Basically, the magnet stops being superconducting (or heats up too much, for quenches happening during charging), and it dumps its energy into the surrounding liquid helium keeping it cold, and thus, the helium instantly boils off, displacing the air in the room.

Quenches and other gaseous discharges (like a nitrogen tank boiling off) are dangerous because you can suffocate without even realizing it. Your body doesn't get the signal of high CO2 levels warning you of danger and you just pass out and die if you linger around it and there isn't enough ventilation or an O2 alarm.

 

[uclaLabrat]

Basically, the magnet stops being superconducting (or heats up too much, for quenches happening during charging), and it dumps its energy into the surrounding liquid helium keeping it cold, and thus, the helium instantly boils off, displacing the air in the room.

Quenches and other gaseous discharges (like a nitrogen tank boiling off) are dangerous because you can suffocate without even realizing it. Your body doesn't get the signal of high CO2 levels warning you of danger and you just pass out and die if you linger around it and there isn't enough ventilation or an O2 alarm.

I was under the impression a catstrophic quench could also result in physical damage not unlike an actual explosion, so good to hear the biggest risk is just going night night for the rest of time 🤣

 

[uclaLabrat]

TSA should have everyone pass by an MRI machine.

Super fun for folks to get their pacemakers ripped out of their chest.

 

[hal2kilo]

Super fun for folks to get their pacemakers ripped out of their chest.

Forgot the slash s.

 

[uclaLabrat]

Forgot the slash s.

I feel sheeeeeeeeepish.

 

[Brainonska511]

I was under the impression a catstrophic quench could also result in physical damage not unlike an actual explosion, so good to hear the biggest risk is just going night night for the rest of time 🤣

It can physically damage the coil because of the rapid heating, but I don't think it's likely to be explosive. Maybe a pressure release valve blowing off. So if you try to charge it back up again, it could immediately quench, or the coil could just be fucked.

Our magnet had like a low pressure release valve on the helium dewar: anything over a few PSI would cause it to softly vent to keep the pressure down.

 

[Sunburn74]

Why did he bring a gun to a hospital? Who goes to a hospital and says "I need to remember to pack heat"

 

[dawp]

We used to just tell patients to dress like they were going to the gym but then we started having a problem with patients wearing Copper Fit underwear which would get uncomfortably warm never mind potentially wreaking havoc with image quality.

hmm, roasted nuts, hard to believe people can be the dumb but then not.