This is the industry I work in. That button, rest assured, is there. It's called a quench. It immediately shuts the magnet down by evacuating helium in an instant. The magnets use liquid Helium which is dangerous in itself. The vent needs to be well away from any area a person could be because it shoots that out and deep freezes anything in it's path. It also displaces oxygen so if the vent fails, and the room fills with helium, it will kill anyone in the room. That happened to a MRI tech not too long ago. Oh, and a MRI is good for 3 or 4 quenches before it's no longer any good. And each quench costs about $30,000 to refill with Helium. And the magnet costs roughly a million bucks. So a quench is a dire emergency situation, which this was.
As far as the magnet goes, there is massive amounts of training involved. The manufacturer (in this case our competition - GE) will spend at least three days training the clinical team. They will drive home the dangers of the magnet and the importance of keeping all ferrous material outside the gauss zone which extends in an oval around the magnet. Then the clinical team should have MRI leads who train others on the risks. Honestly, it takes such a massive lapse of judgement to get a hospital bed anywhere near a MRI that it's shocking to me that it ever happens. The MRI tech must have been away from the room and some numbnutz must have just wheeled the bed in unnoticed.
I've done MRI training of course. It's fascinating stuff. one exercise they do is they have an adjustable wrench on a rope. You hold the rope and as you get closer to the magnet, that wrench really wants to go in there. It's an effort to hold it back. It affects non-ferrous metallic objects as well, but not in a dangerous way. If you take a quarter and set it on end it will act like it's in zero gravity. It will slowly twist around or fall in slow motion because the magnetic flux interacts with the material. Pretty cool stuff.
Good explanation Bob. I've never had an MRI. Got a few chunks of metal in me I would not want to be removed with a magnet.
Yeah, they have a standardized list of things they ask. One of the questions is "Have you ever got metal in your eye?", as in a work related injury. My mom was going in for one and they didn't ask the questions. Not to mention she just had a stroke, so she couldn't really talk anyway. She had a pacemaker that they didn't know about, even though it was done at that very hospital. My then wife didn't think it was okay to get a MRI with a pacemaker and she stated that to the tech just before wheeling mom in. The tech said people with pacemakers can absolutely NOT have a MRI, so crisis averted. But had the wife not been there, it probably would have killed her. This was well before my experience with MRIs and
10-28-2023, 10:16 AM
