Don't bring your office chair for your MRI!
 

Homigosh! Check out these fun pictures of large metallic objects stuck to MRI machines!

http://www.simplyphysics.com/flying_objects.html#

sheesh, I had no idea.:eek: I loved the movie..Haha.

:) Hi Nancy,

Like Sally, I had no idea of the strength of the MRI when it is on. And to think we willingly place out whole bodies inside to shoot the tube?????:eek:

I was worried about my ability to get an MRI after I had my port implanted. Luckily, it is not a problem.

My father,however, has a pace maker and cannot ever have an MRI. That magnet would rip that thing right out of his chest!

The magnet is always on. Even when the RF isn't pulsing and the machine isn't scanning anyone, the magnetic field is constant. These superconducting magnets take a long time to ramp-up to the target field strength, and they use liquid helium to keep the magnet just above absolute zero, which lets the current flow through the magnet's miles of wire indefinitely.

Again, it's always on...24/7/365.

So, Rex, what's the funniest or scariest thing you ever saw stuck to an MRI machine?

Oh, I suppose your outfit was so on top of things that nothing metallic ever got in YOUR MRI room... you probably even made people discard their phasers and tricorders before entering. :)

Nancy

The most annoying metallic objects were hairpins. We would get old ladies with more hairpins than hairs! And they'd always leave a few in, so when we did the scout images we'd see a big black hole where there should have been a brain. Taking them out on the table is very risky, because it's so easy for them to slip out of your hand...and if they get loose and fly into the scanner, you have to go in and find them.

We were always very careful...it's easier to get a patient killed than you'll ever know. When a piece of metal gets loose near the magnet, it seeks out the center of the magnet, which happens to be where the patient's head is. And the bigger the object, the stronger the pull is. We've had hospital stretchers stuck to the magnet...if you try to jerk them off it too fast, you can cause the magnet windings to torque, which can cause a quick build-up of heat (relative to the near-absolute zero temperature in the magnet). At that point, the magnet can "quench", i.e., to boil-off all the cryogenic helium inside it. The liquid helium turns to gas and bursts from the magnet, displacing the oxygen in the room in the process. If you don't get a door open quickly, you could suffocate. We were trained to drop to the floor if this happens, as the helium is lighter than air.

Bet you didn't know that one. :)

Mostly, metal in the scanner is a nuisance; it confounds the technologist and makes the scan a real hassle. People with dental implants (me), or worse, braces, make brain imaging very difficult to perform. The biggest worry are metallic implants like aneurysm clips in the brain. Just moving a patient into the magnet can cause them to twist - even if they're not ferromagnetic! Eddy currents created by moving any metal through the magnetic field (basic electrophysics) can affect the implants.

The funniest thing I ever saw in my radiology days was in the emergency room (actually, there are about 100 funniest things I ever saw in the emergency room). But this one stood out...I had to x-ray a patient's abdomen (called a KUB), and when I walked in he was running around the perimeter of the room. In discomfort. I got him to lie down and took an x-ray..went to develop it and saw a slender tube-like, air-filled structure. I didn't know what the heck it was, this cylinder of air...then, I noticed a small spring at one end, like the little old spring inside the average ball point pen. I found out later (from an OR tech) that it was a bottle of Vitalis Super-Hold hair gel with the convenient pump-action nozzle...somehow (and for some reason) inserted into his rectum.

You can't make this stuff up. :)

Why can't you just use a metal detector to screen little old ladies and other forgetful folks before they go in? Or tell them that they'd better think REAL hard because if they forgot any metal on/in their body, they could come out dead, disfigured, or whatever you think would scare that particular individual the most. :) Kidding on that one, of course, but really why not metal detectors?

Actually, I DID know about the helium-oxygen disaster thing. I read several sites on MRI safety after having that hot-neck episode, and that one, well, it took my breath away! I presume that remains only a theoretical possiblity and has never happened? Although I did hear about the kid who got killed when an oxygen tank hit him in the head; very sad.

I bet the whole ER staff is still telling your Vitalis story! I'm sure you've seen lots of funny stuff, but do you ever watch the true-life "Untold Stories of the ER" on TV? It's really amazing--and excellent proof of what you said: You can't make this stuff up. I mean, the woman who kept named worms in pockets she cut into her skin... the guy who was removing thumbtacks on the ceiling and had one fall into his mouth and directly into his lung, unbeknownst to anyone until he nearly died... the doctor who hit on using hair-removal wax to get thousands of cactus stickers out of a young girl's skin, etc.

You should start a "Rex's 100 funniest stories" daily feature and keep us amused for 100 days. :)

Nancy

They did give us hand-held metal detectors once long ago...but it's very dififcult to set the things so that they don't pick up a rivet in your jeans. And a metal detector won't detect an internal clip. Usually, the verbal screening process works pretty well. In the real world, waving a beeping wand at people isn't usually well received.

No. :)